<PAGE>
                                                                    EXHIBIT 10.6


                            BASIC LEASE INFORMATION
                            -----------------------
                            (Office Lease Agreement)

     LANDLORD: 14850 QUORUM ASSOCIATES, LTD.

     A.  BUILDING: 14850 QUORUM DRIVE, DALLAS, TEXAS 75240

     B.  ADDRESS (for notices):  C/O LEHMAN BROTHERS, INC.
                                 3 WORLD FINANCIAL CENTER, 29TH FLOOR
                                 NEW YORK, NY 10285

                                 Attn: Lawrence M. Ostow

     C.  TELEPHONE:              212-526-3213

     TENANT:  ObjectSpace, Inc., a Texas Corporation

     A.   PREMISES: The spaces known as Suite Nos. 400 AND 500 as identified on
          Exhibit "B" hereto located on floor(s) 4 AND 5 of the Building as
          described in the Lease.

     B.   ADDRESS (for notices):

     Prior to occupancy:                          During occupancy:
     ObjectSpace, Inc.                            ObjectSpace, Inc.
     14881 Quorum Drive, Suite 400                14850 Quorum Drive, Suite 500
     Dallas, Texas 75240                          Dallas, Texas 75240
     Attn: _______________________                Attn: _______________________
     Telephone: __________________                Telephone: __________________

     BASE RENTAL:
          Commencement Date - April 30, 1998      $ 35,012.40 per month
               May 1, 1998 - April 30, 1999       $ 35,772.86 per month
               May 1, 1999 - April 30, 2000       $ 36,825.36 per month
               May 1, 2000 - April 30, 2001       $ 37,585.82 per month
               May 1, 2001 - April 30, 2002       $ 38,638.32 per month
               May 1, 2002 - March 31, 2003       $ 39,398.77 per month

     SECURITY DEPOSIT:

     A.   Within five (5) days after execution of the Lease by both Landlord and
          Tenant or on the date Tenant first occupies the Premises, whichever is
          earlier, the Security Letter of Credit in the amount of $342,258.31 to
          be held by Landlord as security for Tenant complying with the terms of
          the Lease, as set forth in Section 1(d)(1) of the Lease; and

     B.   Prior to the Commencement of the construction of the Tenant
          Improvements, the Improvement Letter of Credit in the amount of
          $381,414.62, to be held by Landlord as security for the amortization
          of the cost of the Tenant Improvements and Commissions, as set forth
          in Section 1(d)(2), Exhibit "D" of the Lease.


                                   -Page 1-

<PAGE>
                                                                    EXHIBIT 10.6


     PREPAID RENTAL:  $35,012.40 due and payable upon execution of the Lease.

     EXPENSE BASE:  1997 base year.

     RENTABLE AREA IN THE PREMISES:  25,260 square feet of Rentable Area.

     RENTABLE AREA IN THE BUILDING:  84,094 square feet of Rentable Area.

     TENANT'S PRO RATA SHARE:  Thirty percent (30%).

     COMMENCEMENT DATE: The earlier of July 1, 1997, or the date Tenant occupies
the Premises, subject to modification pursuant to Paragraph 3(a) of the Lease.

     LEASE TERM: A period of sixty-nine (69) months from the Commencement Date;
provided that if the Commencement Date is a date other than the first day of a
calendar month the Lease Term shall consist of sixty-nine (69) calendar months
in addition to the remainder of the calendar month in which the Commencement
Date occurs.

     LANDLORD'S AGENT(S):  Transwestern Property Company

     SPACE PLAN APPROVAL DATE:

     PERMITTED USE:  General office.

     The foregoing Basic Lease Information shall be construed in conjunction
with the references thereto contained in other provisions of the Lease and shall
be limited by such other provisions. Each reference in the Lease to any of the
foregoing Basic Lease Information shall be construed to incorporate each term
set forth hereinabove as so limited. In the event of any conflict between any
Basic Lease Information and the Lease, the terms of the Lease shall control.


                                   -Page 2-

<PAGE>
                                                                    EXHIBIT 10.6


                               TABLE OF CONTENTS

<TABLE>
<CAPTION>

                                                                                 Page
                                                                                 ----
<S>  <C>                                                                           <C>
1.   Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
2.   Lease Grant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
3.   Lease Term. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
4.   Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
5.   Base Rental . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
6.   Security Deposit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
7    Services to be Furnished by Landlord. . . . . . . . . . . . . . . . . . . . . .7
8.   Improvements to be Made by Landlord . . . . . . . . . . . . . . . . . . . . . .8
9.   Graphics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
10.  Repairs and Alterations by Tenant . . . . . . . . . . . . . . . . . . . . . . .8
11.  Use of Electrical Services by Tenant. . . . . . . . . . . . . . . . . . . . . .9
12.  Entry by Landlord . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
13.  Assignment and Subletting . . . . . . . . . . . . . . . . . . . . . . . . . . 10
14.  Mechanic's Liens. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
15.  Property Insurance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
16.  Liability and Worker's Compensation Insurance . . . . . . . . . . . . . . . . 13
17.  Indemnity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
18.  Evidence of Insurance . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
19.  Casualty Damage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
20.  Damages from Certain Causes . . . . . . . . . . . . . . . . . . . . . . . . . 15
21.  Condemnation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
22.  Events of Default/Remedies. . . . . . . . . . . . . . . . . . . . . . . . . . 15
23.  Tenant Remedies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
24.  No Waiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
25.  Event of Bankruptcy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
26.  Peaceful Enjoyment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
27.  Substitution. [Intentionally Omitted] . . . . . . . . . . . . . . . . . . . . 21
28.  Holding Over. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
29.  Subordination to Mortgage . . . . . . . . . . . . . . . . . . . . . . . . . . 22
30.  Attorney's Fees . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
31.  Notice. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
32.  Severabilily. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
33.  Recordation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
34.  Governing Law . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
35.  Force Majeure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
36.  Time of Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
37.  Transfers by Landlord . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
38.  Commissions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
39.  Joint and Several Liability . . . . . . . . . . . . . . . . . . . . . . . . . 23
40.  Authority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
41.  Financial Condition of Tenant . . . . . . . . . . . . . . . . . . . . . . . . 23
42.  Effect of Delivery of This Lease. . . . . . . . . . . . . . . . . . . . . . . 23
43.  Entire Agreement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
44.  Landlord's Lien . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

</TABLE>


                                   -Page 3-
<PAGE>
                                                                    EXHIBIT 10.6


                                OFFICE LEASE AGREEMENT

     This Office Lease Agreement (the "Lease"), made and entered into on this
the 5th day of May, 1997, between 14850 QUORUM ASSOCIATES, LTD., a Texas limited
partnership ("LANDLORD") and OBJECTSPACE, INC., a Texas corporation ("TENANT").

                                W I T N E S S E T H:

     1.   DEFINITIONS: The following are definitions of some of the defined
terms used in this Lease. The definition of other defined terms are found
throughout this Lease.

          (a)  "BUILDING" shall mean the office building located upon the real
     property (the "Property") described in EXHIBIT "A" attached hereto and
     incorporated herein together with all appurtenances thereto.

          (b)  "BASE RENTAL" shall mean the following sums per month for each of
     the stated years of the Lease Term for a total of $2,569,378.79 during the
     Lease Term, all as adjusted pursuant to EXHIBIT "C" hereto:

<TABLE>

          <S>                                     <C>
          Commencement Date - April 30, 1998      $ 35,012.40 per month
               May 1, 1998 - April 30, 1999       $ 35,772.86 per month
               May 1, 1999 - April 30, 2000       $ 36,825.36 per month
               May 1, 2000 - April 30, 2001       $ 37,585.82 per month
               May 1, 2001 - April 30, 2002       $ 38,638.32 per month
               May 1, 2002 - March 31, 2003       $ 39,398.77 per month

</TABLE>

     The Base Rental due for the first month during the "LEASE TERM"
     (hereinafter defined) has been deposited with Landlord by Tenant
     contemporaneously with the execution hereof.

          (c)   "BASIC COSTS" shall mean all direct and indirect costs and
     expenses incurred in connection with the Building as more fully defined in
     EXHIBIT "C" attached hereto.

          (d)  "SECURITY DEPOSIT" shall mean:

               (1)  An irrevocable, annually renewable letter of credit (the
          "SECURITY LETTER OF CREDIT") to the Landlord's benefit, on terms
          acceptable to Landlord, in the amount of $342,258.31, shall be
          delivered by Tenant to Landlord within five (5) days after execution
          of this Lease by both Landlord and Tenant or on the date Tenant first
          occupies the Premises, whichever is earlier. The Security Letter of
          Credit shall be held by Landlord as security for Tenant's obligations
          under this Lease. If Tenant does not renew the Security Letter of
          Credit and deliver to Landlord the original, renewed letter of credit
          (thereafter defined as the "SECURITY LETTER OF CREDIT") at least
          thirty (30) days before the end of the annual term of each annual
          Security Letter of Credit, on that date which is twenty-nine (29) days
          before the end of that year's Security Letter of Credit, Landlord may
          cash in that Security Letter of Credit and thereafter hold the cash as
          a deposit in lieu of the Security Letter of Credit. Such sum shall be
          held by Landlord, who shall have no obligation to account to Tenant
          for any interest thereon.  In the last ten months of the Lease Term,
          Tenant may, at its option, redeem from Landlord the Security Letter of
          Credit by substituting for the Security Letter of Credit a sum of cash
          equal to the Base


                                   -Page 1-
<PAGE>
                                                                    EXHIBIT 10.6


          Rental due during the last twelve months of the Lease Term. If the
          Tenant chooses this option, the stated sum of cash shall be deemed
          to be the "SECURITY DEPOSIT". Each month thereafter, a portion of
          the Security Deposit shall be applied to the Base Rental due in
          each consecutive month. It is the parties' intention that at the
          end of the Lease Term the Security Deposit shall equal the Base
          Rental due for the last two months of the Lease Term. Landlord
          shall have no obligation to account to Tenant for interest on the
          Security Deposit; and

               (2)  An additional, irrevocable, annual renewable Letter of
          Credit (the "IMPROVEMENT LETTER OF CREDIT") to Landlord's benefit, on
          terms acceptable to Landlord, in the amount of $381,414.62, shall be
          delivered by Tenant to Landlord on execution of this Lease. If Tenant
          does not renew the Improvement Letter of Credit and deliver to
          Landlord the original, renewed letter of credit (thereafter defined as
          the "IMPROVEMENT LETTER OF CREDIT") at least thirty (30) days before
          the end of the annual term of each annual Improvement Letter of
          Credit, on that date which is twenty-nine (29) days before the end of
          that year's Improvement Letter of Credit, Landlord may cash in that
          Improvement Letter of Credit and thereafter hold the cash as a deposit
          in lieu of the Improvement Letter of Credit.  Such sum shall be held
          by Landlord, who shall have no obligation to account to Tenant for any
          interest thereon. The Improvement Letter of Credit shall expire on the
          date on which Tenant's accumulated payments of Basic Rental since the
          Commencement Date equal the total sum secured by the Improvement
          Letter of Credit.

          (e)  "COMMENCEMENT DATE" shall mean the earlier of the date that
     Tenant actually occupies the Premises or July 1, 1997 (except as the same
     may be delayed pursuant to the provisions of Paragraph 3(a) hereof). (See
     Addendum, Section 4).

          (f)  "LEASE TERM" shall mean a term commencing on the Commencement
     Date and continuing for sixty-nine (69) full calendar months (plus any
     partial calendar month in which the Commencement Date occurs).

          (g)  "PREMISES" shall mean the suite of offices located within the
     Building and outlined on EXHIBIT "B" to this Lease. The Premises are
     stipulated for all purposes to contain 25,260 square feet of "Rentable
     Area" (as defined below).

          (h)  "RENTABLE AREA" shall mean the area contained within the demising
     walls of the Premises and any other area designated for the exclusive use
     of Tenant plus an allocation of the Tenant's pro rata share of the square
     footage of the "Common Areas" and the "Service Areas" (as defined below).
     The Rentable Area in the Building shall be deemed to be 84,094 square feet.
     The estimates of Rentable Area within the Premises and within the Building
     as set forth herein may be revised at Landlord's election if Landlord's
     architect determines such estimate to be inaccurate in any material degree
     after examination of the final drawings of the Premises and the Building.
     (See Addendum, Section 1).

          (i)  "COMMON AREAS" shall mean those areas devoted to corridors,
     elevator foyers, mail rooms, restrooms, mechanical rooms, elevator
     mechanical rooms, janitorial closets, electrical and telephone closets,
     vending areas, and lobby areas (whether at ground level or otherwise), and
     other similar facilities provided for the common use or benefit of tenants
     generally and/or the public.


                                   -Page 2-
<PAGE>
                                                                    EXHIBIT 10.6


          (j)  "SERVICE AREAS" shall mean those areas within the outside walls
     of the Building used for stairs, elevator shafts, flues, vents, stacks,
     pipe shafts and other vertical penetrations (but shall not include any such
     areas for the exclusive use of a particular tenant).

          (k)  "BUILDING STANDARD", when used herein, shall mean the type,
     brand, quality and/or quantity of materials Landlord designates from time
     to time to be the minimum quality and/or quantity to be used in the
     Building or the exclusive type, grade, quality and/or quantity of material
     to be used in the Building and shall include, but not be limited to, the
     Building Standard Materials defined in the Work Letter Agreement attached
     hereto as EXHIBIT "D".

          (l)  "MAXIMUM RATE", when used herein, shall mean the greatest of the
     rates of interest from time to time permitted under applicable federal and
     state law. To the extent of the applicability of Article 5069-1.04, as
     amended, Texas Revised Civil Statutes, the Maximum Rate shall be the
     highest permitted rate based upon the "indicated rate ceiling", but to the
     extent now or hereafter permitted by Texas law, Landlord may from time to
     time implement, withdraw and reinstate any ceiling as an alternative to the
     indicated rate ceiling, including the right to reinstate the indicated rate
     ceiling.

          (m)  "PRIME RATE" shall mean the per annum interest rate announced by
     Texas Commerce Bank from time to time (whether or not charged in each
     instance) as its prime or base rate.

          (n)  "NORMAL BUSINESS HOURS" for the Building shall mean 7:00 a.m. to
     6:00 p.m. Mondays through Fridays, and 8:00 a.m. to 1:00 p.m. on Saturdays,
     exclusive of the normal business holidays of New Years Day, Memorial Day,
     Independence Day, Labor Day, Thanksgiving Day and Christmas Day.

          (o)  "PREPAID RENTAL" shall mean the sum of $35,012.00 which shall be
     paid by Tenant to Landlord on execution of this Lease. The Prepaid Rental
     shall be applied to the first full month's Base Rental due under this
     Lease.

          (p)  "BUSINESS DAY(S)" shall mean Mondays through Fridays exclusive of
     the normal business holidays of New Year's Day, Memorial Day, Independence
     Day, Labor Day, Thanksgiving Day and Christmas Day.

     2.   LEASE GRANT. Subject to and upon the terms herein set forth, Landlord
leases to Tenant and Tenant leases from Landlord the Premises.

     3.   LEASE TERM.

          (a)  Subject to and upon the terms and conditions set forth in this
     Lease, this Lease shall continue in force for the Lease Term.
     Notwithstanding the Commencement Date provided in Paragraph l(e) of this
     Lease, Tenant's obligation for the payment of rent and the Lease Term shall
     not commence until Landlord has substantially completed all work to be
     performed by Landlord as set forth in the Work Letter Agreement attached
     hereto as EXHIBIT "D"; provided, however, that if Landlord shall be delayed
     in substantially completing said work as a result of any of the following
     (a "DELAY"):


                                   -Page 3-

<PAGE>
                                                                    EXHIBIT 10.6


               (i)    Tenant's failure to furnish information in accordance
          herewith or to respond to any request by Landlord for any approval or
          information within any time period prescribed, or if no time period is
          prescribed, then within three Business Days of such request; or

               (ii)   Tenant's insistence on materials, finishes or
          installations other than Landlord's Building Standard after having
          first been informed by Landlord in writing at or before the time of
          delivery to Tenant of final construction pricing for Tenant's approval
          that such materials, finishes or installations will cause a Delay; or

               (iii)  Tenant's changes in any plans and specifications; or

               (iv)   The performance by a person, firm or corporation employed
          by Tenant in the completion of any work by said person, firm or
          corporation (all such work and such persons, firms or corporations
          being subject to the approval of Landlord); or

               (v)    Any request by Tenant that Landlord delay the completion
          of any of Landlord's work; or

               (vi)   Any breach or default by Tenant in the performance of
          Tenant's obligations under this Lease; or

               (vii)  Any delay resulting from Tenant's having taken possession
          of the Premises prior to its being substantially completed, as defined
          below; or

               (viii) Any reasonably necessary displacement of any of
          Landlord's work from its place in Landlord's construction schedule
          resulting from any of the causes for Delay; or

               (ix)   Any other delay chargeable to Tenant, its agents,
          employees or independent contractors;

     then the commencement of the Lease Term and the payment of rent shall be
     accelerated by the number of days of such Delay but in no event shall such
     commencement be prior to the Commencement Date stipulated in Paragraph 1(e)
     hereof. The Premises shall be deemed to be substantially completed on the
     date that Landlord's architect reasonably determines that all work to be
     performed by Landlord pursuant to this Lease has been performed other than
     punchlist items. The term "punchlist items" as used herein shall mean any
     details of construction, mechanical adjustment or other matter, the
     noncompletion of which does not materially interfere with Tenant's use of
     the Premises. The abatement of rent shall be Tenant's sole remedy and shall
     constitute full settlement of all claims that Tenant might otherwise have
     against Landlord by reason of the Premises not being ready for occupancy by
     Tenant on the Commencement Date. If for any reason Tenant takes possession
     of the Premises prior to substantial completion, except as set forth in the
     next sentence, Tenant's obligation to pay rent shall commence upon the date
     Tenant takes possession of the Premises and Tenant shall indemnify and hold
     Landlord harmless from any liability as a result of Tenant's early
     occupancy of the Premises. Tenant shall have access to the Premises five
     (5) days before the Commencement Date to move in furniture and prepare for
     opening Tenant's business; provided (i) that Tenant shall not conduct
     business from the Premises until the Commencement Date and (ii) that
     Landlord and Tenant prepare a final

                                   -Page 4-
<PAGE>
                                                                    EXHIBIT 10.6


     punchlist before Tenant shall have such access. Landlord's determination
     of the Commencement Date shall be final and binding on all parties for
     all purposes hereof, including, without limitation, determination of the
     date of commencement of the Lease Term and of Tenant's obligation to pay
     rent hereunder. (See Addendum, Sections 2 and 3).

          (b)  The taking of possession of the Premises by Tenant shall be
     conclusive evidence against Tenant that, except for the completion of any
     items which Landlord stipulates in writing are remaining to be done or
     corrected by Landlord, (i) Tenant warrants and represents to Landlord that
     it has conducted its own independent investigation of the Premises and that
     the Premises are suitable for the purpose for which the same are leased,
     (ii) the Property and the Building and each and every part and appurtenance
     thereof are in good and satisfactory condition, except for any defect which
     is not discoverable upon a reasonable inspection, and (iii) Tenant waives
     any defects in the Premises and its appurtenances and in all other parts of
     the Building and the appurtenances thereto, except for any defect which is
     not discoverable upon a reasonable inspection.

     If Tenant intends to vacate the Premises at the end of the Lease Term,
     Tenant will give Landlord ninety (90) days prior written notice of such
     intent to vacate the Premises.

     4.   USE. The Premises shall be used for office purposes (the "PERMITTED
USE") and for no other purpose. Neither Landlord nor its agents or employees
have made any representation or warranty as to the suitability of the Premises
for the conduct of Tenant's business. Tenant agrees not to use or permit the use
of the Premises for any purpose which is illegal, dangerous to life, limb or
property or which, in Landlord's reasonable opinion, creates a nuisance or which
would increase the cost of insurance coverage with respect to the Building. In
the event there shall be any increase in the cost of insurance coverage with
respect to the Building which results from Tenant's acts or conduct of business,
then Tenant hereby agrees to pay the amount of such increase on demand.  Tenant
will conduct its business and control its agents, servants, employees,
customers, licensees, and invitees in such a manner as not to unreasonably
interfere with, annoy or disturb other tenants or Landlord in the management of
the Building. Tenant will maintain the Premises in a clean and healthful
condition, and comply with all laws, ordinances, orders, rules and regulations
of any governmental entity with reference to the use, condition or occupancy of
the Premises. Tenant covenants not to introduce any toxic material into or near
Building. Without limiting the generality of the foregoing, Tenant shall not
store, use or dispose of any toxic material in or near the Building.  Tenant
shall comply with all applicable federal, state, and local laws or ordinances
pertaining to the storage, use or disposal of any toxic material. Tenant will
comply with the rules and regulations of the Building adopted and altered by
Landlord from time to time and will cause all of its agents, employees, invitees
and visitors to do so. All changes to such rules and regulations will be sent by
Landlord to Tenant in writing. A copy of the existing rules and regulations is
attached hereto as Exhibit "H" and made a part hereof. Tenant agrees not to
commit or allow any waste to be committed on any portion of the Premises, and at
the termination of this Lease to deliver up the Premises to Landlord in as good
condition as at the Commencement Date, ordinary wear and tear excepted. Tenant
will not conduct or permit to be conducted any sale by auction on the Premises.
(See Addendum, Section 5).

     5.   BASE RENTAL.

          (a)  Tenant covenants and agrees to pay during the Lease Term, to
     Landlord, without any setoff or deduction whatsoever, the Base Rental, and
     all such other sums of money as shall become due hereunder as additional
     rent, all of which are sometimes herein collectively called

                                   -Page 5-
<PAGE>
                                                                    EXHIBIT 10.6


     "rent." In the event of nonpayment of any such rent, Landlord shall be
     entitled to exercise all such rights and remedies as are herein provided
     in the case of the nonpayment of Base Rental. Except as otherwise
     provided herein, the annual Base Rental for each calendar year or
     portion thereof during the Lease Term, together with any estimated
     adjustment thereto pursuant to EXHIBIT "C" hereof then in effect, shall
     be due and payable in advance in twelve (12) equal installments on the
     first day of each calendar month during the initial term of this Lease
     and any extensions or renewals hereof, and Tenant hereby agrees to pay
     such Base Rental and any adjustments thereto to Landlord at Landlord's
     address provided herein (or such other address as may be designated by
     Landlord in writing from time to time) monthly, in advance, and without
     demand. If the term of this Lease commences on a day other than the
     first day of a month or terminates on a day other than. the last day of
     a month, then the installments of Base Rental and any adjustment thereto
     for such month or months shall be prorated, based on the number of days
     in such month. The Base Rental for the first partial month, if any,
     shall be payable at the beginning of said period. All such payments
     shall be by a good and sufficient check (subject to collection) drawn on
     a bank acceptable to Landlord. No payment by Tenant or receipt or
     acceptance by Landlord of a lesser amount than the correct installment
     of rent due under this Lease shall be deemed to be other than a payment
     on account of the earliest rent due hereunder, nor shall any endorsement
     or statement on any check or any letter accompanying any check or
     payment be deemed an accord and satisfaction, and Landlord may accept
     such check or payment without prejudice to Landlord's right to recover
     the balance or pursue any other remedy provided by this Lease or
     applicable law. The acceptance by Landlord of an installment of rent on
     a date after the due date of such payment shall not be construed to be a
     waiver of Landlord's right to declare a default for any other late
     payment. If Tenant fails to timely pay any two (2) installments of rent,
     Landlord may require Tenant to pay rent (as estimated by Landlord, if
     necessary) quarterly in advance, and, in such event, all future payments
     shall be made on or before the due date in cash or by cashier's check or
     money order, and the delivery of Tenant's collectible personal or
     corporate check shall no longer constitute payment thereof. Any
     acceptance of Tenant's collectible personal or corporate check
     thereafter by Landlord shall not be construed as a waiver of the
     requirement that such payments be made in cash or by cashier's check or
     money order. All amounts received by Landlord from Tenant hereunder
     shall be applied first to the earliest accrued and unpaid rent then
     outstanding.

          (b)  All installments of rent not paid when due and payable shall bear
     interest until paid at a per annum rate equal to the lesser of (i) the
     Prime Rate plus five percent (5%) or (ii) the Maximum Rate.

          (c)  The Base Rental payable hereunder shall be adjusted upward from
     time to time in accordance with the provisions of EXHIBIT "C" attached
     hereto and incorporated herein for all purposes.

          (d)  See additional provisions regarding Base Rental in Paragraph 6.

     6.   SECURITY DEPOSIT. The Security Deposit shall be held by Landlord
without liability for interest and as security for the performance by Tenant of
Tenant's covenants and obligations under this Lease including but not limited to
those set forth in Paragraph 10 hereof, it being expressly understood that the
Security Deposit shall not be considered an advance payment of rent, except as
set forth later in this paragraph, or a measure of Tenant's liability for
damages in case of default by Tenant.  Landlord may commingle the Security
Deposit with Landlord's other funds. Landlord may, from time to time, without
prejudice to any other remedy, use the Security Deposit to the extent necessary
to make good

                                   -Page 6-
<PAGE>
                                                                    EXHIBIT 10.6



any arrearages of rent or to satisfy any other covenant or obligation of
Tenant hereunder. Following any such application of the Security Deposit,
Tenant shall pay to Landlord on demand the amount so applied in order to
restore the Security Deposit to its original amount.  If Tenant is not in
default at the termination of this Lease, the balance of the Security Deposit
remaining after any such application shall be returned by Landlord to Tenant.
If Landlord transfers its interest in the Premises during the term of this
Lease, Landlord may assign the Security Deposit to the transferee and
thereafter shall have no further liability for the return of such Security
Deposit.  Tenant agrees to look solely to such transferee or assignee or
successor thereof for the return of the Security Deposit. Landlord and its
successors and assigns shall not be bound by any actual or attempted
assignment or encumbrance of the Security Deposit by Tenant.

     7.   SERVICES TO BE FURNISHED BY LANDLORD. Landlord shall provide to
Tenant, at no additional or separate charge to Tenant, the level and quality of
services typically provided by Landlords of office buildings comparable to the
Building within a three mile radius of the Building and Tenant shall be entitled
to install and operate photocopiers, telephone and telecopy equipment, word
processing equipment, computers and other equipment customarily used in
comparable office space in such area without additional charge. Landlord agrees
to furnish Tenant the following services:

          (a)  Hot and cold water at those points of supply provided for general
     use of tenants in the Building, central heat and air conditioning in
     season, at such temperatures and in such amounts as are considered standard
     for buildings comparable to the Building within a three mile radius of the
     Building or as required by governmental authority; provided, however,
     heating and air conditioning service at times other than for Normal
     Business Hours for the Building shall be furnished only upon the written
     request of Tenant delivered to Landlord prior to 3:00 p.m. at least one
     Business Day in advance of the date for which such usage is requested.
     Tenant shall bear the entire cost of additional service as such costs are
     determined by Landlord from time to time. Tenant shall comply with energy
     conservation programs implemented by Landlord by reason of enacted laws or
     ordinances.

          (b)  Routine maintenance and electric lighting service for all Common
     Areas and Service Areas of the Building in the manner and to the extent
     deemed standard for buildings comparable to the Building within a three
     mile radius of the Building.

          (c)  Janitor service on Business Days; provided, however, if Tenant's
     floor covering or other improvements require special treatment, Tenant
     shall pay the additional cleaning cost attributable thereto as additional
     rent upon presentation of a statement therefor by, Landlord.

          (d)  Subject to the provisions of Paragraph 11 hereof, facilities to
     provide all electrical current required by Tenant in its use and occupancy
     of the Premises. (See Addendum, Section 9).

          (e)  All fluorescent bulb replacement in the Premises necessary to
     maintain the lighting provided by Landlord as set forth in the Work Letter
     Agreement attached hereto as EXHIBIT "D" as a part of the Building Standard
     Materials and fluorescent and incandescent bulb replacement in the Common
     Areas and Service Areas.

          (f)  Passenger elevators for ingress and egress to and from the floor
     of the Premises during Normal Business Hours and with at least one
     passenger elevator available at all other times.

                                   -Page 7-
<PAGE>
                                                                    EXHIBIT 10.6


          (g)  Access control to the Building during other than Normal Business
     Hours shall be provided in such form as Landlord deems appropriate. Tenant
     shall cooperate fully in Landlord's efforts to maintain access control to
     the Building and shall follow all regulations promulgated by Landlord with
     respect thereto. (See Addendum, Section 6).

     Except as otherwise expressly provided herein, the failure by Landlord to
     any extent to furnish, or the interruption or termination of these defined
     services in whole or in part, resulting from adherence to laws, regulations
     and administrative orders, FORCE MAJEURE or any other causes beyond the
     reasonable control of Landlord shall not render Landlord liable in any
     respect nor be construed as an eviction of Tenant, nor work an abatement of
     rent, nor relieve Tenant from the obligation to fulfill any covenant or
     agreement hereof Should any of the equipment or machinery used in the
     provision of such services for any cause cease to function properly,
     Landlord shall use reasonable diligence to repair such equipment or
     machinery but, except as otherwise expressly provided herein, Tenant shall
     have no claim for offset or abatement of rent or damages on account of an
     interruption in service thereby or resulting therefrom. Except as expressly
     provided herein, Landlord shall not be required to make any repairs to or
     maintain the Premises. (See Addendum, Section 8).

     Notwithstanding anything to the contrary set forth in this Lease, if there
     is any material slow-down, interruption or stoppage of any of the services
     required to be provided by Landlord pursuant to this Lease, and if Landlord
     has failed to commence to cure or remedy such problem within ten (10) days
     after Tenant's prior written notice thereof, or if Landlord should fail
     thereafter to proceed diligently to remedy such problem, then provided that
     the problem has a material adverse effect on the habitability of the
     Premises or a portion thereof and Tenant has ceased to use or occupy the
     portion of the Premises affected, Tenant shall have the right to abate rent
     by submitting to binding arbitration.

     8.   IMPROVEMENTS TO BE MADE BY LANDLORD. Except as otherwise provided in
the Work Letter Agreement attached hereto as Exhibit "W" all installations and
improvements now or hereafter placed on or in the Premises shall be subject to
the provisions of Paragraph 10 hereof and shall be for Tenant's account and at
Tenant's cost (and Tenant shall pay ad valorem taxes and increased insurance
thereon or attributable thereto), which cost shall be payable by Tenant to
Landlord upon demand as additional rent.

     9.   GRAPHICS. Landlord shall provide and install, at Tenant's cost, all
letters or numerals on  the exterior of the Premises; all such letters and
numerals shall be in the standard graphics for the Building and no others shall
be used or permitted on the Premises without Landlord's prior written consent.
Tenant acknowledges that the standard Building graphics are acceptable to
Tenant. (See Addendum, Section 7).

     10.  REPAIRS AND ALTERATIONS BY TENANT. Tenant covenants and agrees with
Landlord, at Tenant's own cost and expense, to keep the Premises in good
condition and repair and to repair or replace any damage done to the Building,
or any part thereof, caused by Tenant or Tenant's agents, servants, employees,
customers, licensees, or invitees. Tenant further covenants and agrees that such
repairs shall restore the Building to as good a condition as it was in prior to
such damage and that such repairs shall be effected in compliance with all
applicable laws. If Tenant fails to make such repairs or replacements promptly,
Landlord may, at its option, make such repairs or replacements, and Tenant shall
pay the cost thereof to the Landlord on demand as additional rent. Tenant agrees
with Landlord not to make or allow to be made any alterations to the Premises,
or place signs on the Premises which are

                                   -Page 8-
<PAGE>
                                                                    EXHIBIT 10.6


visible from outside the Premises, without first obtaining the written
consent of Landlord in each such instance. If Landlord gives its consent, no
such alterations will proceed without Landlord's prior written approval of
(i) Tenant's contractor, (ii) certificates of insurance by Tenant's
contractor for public liability and automobile liability and property damage
insurance as set forth in Paragraph 16, and (iii) detailed plans and
specifications for such work. Any and all alterations, additions and
improvements to the Premises, all attached furniture, equipment and fixtures,
and any unattached and movable equipment, furniture, trade fixtures or other
personalty which was acquired with funds provided by or on behalf of Landlord
shall become the property of Landlord upon termination of this Lease. In
addition, all other personal property which shall remain in the Premises for
more than seven (7) days following either the termination of this Lease or
the entry of the Premises by Landlord following Tenant's default hereunder
shall, at Landlord's option, become the property of Landlord. Landlord may,
nonetheless, require Tenant to remove such fixtures, furniture, trade
fixtures, equipment, improvements, alterations, additions and personal
property installed on or located in the Premises as are designated by
Landlord at the time Landlord approves the plans or such installments (the
"REQUIRED REMOVABLES") at Tenant's sole cost. In the event that Landlord so
elects, and Tenant fails to remove the Required Removables, Landlord may
remove the Required Removables at Tenant's cost, and Tenant shall pay
Landlord on demand all costs incurred in removing, storing and/or disposing
of the Required Removables. Landlord may also require Tenant to provide
Landlord, at Tenant's sole cost and expense, a payment and performance bond
in form acceptable to Landlord, in a principal amount not less than one and
one-half times the estimated cost of such alterations, to insure Landlord
against any liability for mechanic's or materialman's liens and to insure
completion of the work. Lessor will have the right to construct or permit
construction of tenant improvements in or about the Building for existing and
new tenants and to alter any public areas in and around the Property.
Notwithstanding anything which may be contained in this Lease, Tenant
understands this right of Landlord and agrees that such construction will not
be deemed to constitute a breach of this Lease by Landlord and Tenant waives
any such claim which it might have arising from such construction. Tenant
will not make repairs to the Premises at the cost of Landlord, whether by
deduction of rent or otherwise and will not vacate the Premises or terminate
the Lease with abatement or termination of rent because repairs are not made.
If during the Lease Term, any alteration, addition or change to the Premises
is required by legal authorities, Tenant, at its sole expense, shall promptly
make same. Landlord will not be liable for any failure to make any repairs or
perform any maintenance and there will be no abatement of rent, nor liability
of Landlord by reason of any injury to or interference with Tenant's business
arising from the making or failure to make any repair, alteration or
improvement in or to any portion of the Premises or to Tenant's fixtures,
appurtenances and equipment.

     11.  USE OF ELECTRICAL SERVICES BY TENANT. Tenant's use of electrical
services furnished by Landlord shall not exceed, either in voltage, rated
capacity, or overall load that which Landlord deems to be standard for the
Building. In the event Tenant shall request that it be allowed to consume
electrical services in excess of that deemed by Landlord to be standard for the
Building, Landlord may refuse to consent to such usage or may consent upon such
conditions as Landlord elects (including the requirement that submeters be
installed at Tenant's expense). However, Tenant shall have the right to install
its own HVAC system (subject to Landlord s approval of the size and location of
such system) at Tenant's expense which system shall be separately metered and
for which Tenant shall be fully responsible, both for the monthly utility
charges therefor and for the maintenance and repair thereof. Tenant additionally
shall pay to Landlord an administrative fee equal to five percent (5%) of (i)
any utility charges for this additional HVAC system and (ii) any repairs thereof
which Landlord must perform if Tenant does not. At the end of the Lease Term,
the HVAC system which Tenant installs shall become the property Landlord
(subject to Landlord s approval of size and location of such system).

                                   -Page 9-

<PAGE>
                                                                    EXHIBIT 10.6


     12.  ENTRY BY LANDLORD. Tenant agrees to permit Landlord or its agents
or representatives to enter into and upon any part of the Premises at all
reasonable hours (and in emergencies at all times, by any means Landlord may
deem proper, and without liability therefor) to inspect the same, or to show
the Premises to prospective purchasers, mortgagees, tenants (to tenants only
during last year of Lease Term) or insurers, or to clean or make repairs,
alterations or additions thereto, and Tenant shall not be entitled to any
abatement or reduction of rent by reason thereof. Landlord will at all times
have and retain a key with which to unlock all of the doors in, upon and
about the Premises, excluding Tenant's vaults, safes and filing cabinets.
Tenant will not alter any lock or install a new or additional lock or any
bolt on any door of the Premises without the prior written consent of
Landlord, which will not be unreasonably withheld. If Landlord gives its
consent, such work shall be undertaken by a locksmith approved by Landlord,
at Tenant's sole cost, and Tenant will furnish Landlord with a key. Landlord
retains the right to charge Tenant for restoring any altered doors to their
condition prior to the installation of the new or additional locks.

     13.  ASSIGNMENT AND SUBLETTING.

          (a)  Tenant shall not assign, sublease, transfer or encumber this
     Lease or any interest therein or grant any license, concession or other
     right of occupancy of the Premises or any portion thereof or otherwise
     permit the use of the Premises or any portion thereof by any party other
     than Tenant (any of which events is hereinafter called an "ASSIGNMENT")
     without the prior written consent of Landlord. Any such attempted
     assignment in violation of the terms and covenants of this Paragraph shall,
     at Landlord's option, exercisable in Landlord's sole and absolute
     discretion, be void. Consent by Landlord to one or more assignments shall
     not operate as a waiver of Landlord's rights as to any subsequent
     assignments. In addition, Tenant shall not, without Landlord's consent,
     publicly offer to assign the Lease nor advertise the Lease for assignment
     in any media, including but not limited to newspapers, periodicals, radio,
     television, circulars or brochures. In the event Tenant or any agent,
     representative or broker acting on behalf of Tenant or with Tenant's
     knowledge violates the provisions of the foregoing sentence, in addition to
     all of the remedies which Landlord may have at law, in equity, or pursuant
     to the terms of this Lease, Landlord shall be entitled to seek injunctive
     relief preventing such action and Tenant shall be responsible for all costs
     incurred by Landlord in connection with seeking such injunctive relief.

          (b)  If Tenant requests Landlord's consent to an assignment, Tenant
     shall submit to Landlord, in writing, the name of the proposed assignee and
     the nature and character of the business of the proposed assignee, the
     term, use, rental rate and all other material terms and conditions of the
     proposed assignment, including, without limitation, evidence satisfactory
     to Landlord that the proposed assignee has a financial strength equal to or
     greater than Tenant's. Landlord shall either (i) consent to or refuse to
     consent to such assignment in writing (but no such consent to an assignment
     shall relieve Tenant or any guarantor of Tenant's obligations under this
     Lease of any liability hereunder), or (ii) negotiate directly with the
     proposed assignee and (in the event Landlord is able to reach agreement
     with such proposed assignee) upon execution of a lease with such assignee,
     terminate this Lease (in part or in whole, as appropriate) upon ninety (90)
     days' notice. If Landlord should fail to notify Tenant in writing of its
     decision within a sixty (60) day period after the later of the date
     Landlord is notified in writing of the proposed assignment or the date
     Landlord has received all required information concerning the proposed
     assignee and the proposed assignment, Landlord shall be deemed to have
     refused to consent to such assignment, and to have elected to keep this
     Lease in full force and effect. In the event Landlord consents to any such
     assignment, the assignment shall be on a form approved by


                                   -Page 10-
<PAGE>
                                                                    EXHIBIT 10.6


     Landlord, and Tenant shall bear all costs and expenses incurred by Landlord
     in connection with the review and approval of such documentation. Landlord
     shall not withhold its approval of a proposed assignment or sublease
     unreasonably, provided Landlord approves the financial strength of, and use
     of the Premises proposed by, the proposed assignee or sublessee. Landlord
     shall have no right to terminate this Lease if Tenant assigns or subleases
     the Premises to an affiliate of Tenant, provided that the financial
     strength of the affiliate is equal to or greater than Tenant's and provided
     that Tenant shall remain liable under this Lease. An "AFFILIATE" shall be
     defined as any entity which owns at least fifty-one percent (51%) of the
     equity and control of Tenant or an entity in which Tenant owns at least
     fifty-one percent (51%) of the equity and control.

          (c)  All cash or other proceeds of any assignment or sublease of
     Tenant's interest in this Lease and/or the Premises, whether consented to
     by Landlord or not, shall be paid to Landlord notwithstanding the fact that
     such proceeds exceed the rentals called for hereunder, unless Landlord
     agrees to the contrary in writing, and Tenant hereby assigns all rights it
     might have or ever acquire in any such proceeds to Landlord. In addition to
     the rent hereunder, Tenant hereby covenants and agrees to pay to Landlord
     all rent and other consideration which it receives which is in excess of
     the rent payable hereunder within ten (10) days following receipt thereof
     by Tenant. This covenant and assignment shall benefit Landlord and its
     successors in ownership of the Building and shall bind Tenant and Tenant's
     heirs, executors, administrators, personal representatives, successors and
     assigns. In addition to any other rights and remedies which Landlord may
     have hereunder, at law or in equity, in the event Tenant has failed to pay
     any rent due hereunder on or before five (5) days following the date on
     which it is due, Landlord shall have the right to contact any assignee or
     subtenant and require that from that time forward all payments made
     pursuant to the assignment or sublease shall be made directly to the
     Landlord. Any assignee or subtenant of Tenant's interest in this Lease (all
     such assignees or subtenants being hereinafter referred to as
     "SUCCESSORS"), by occupying the Premises and/or assuming Tenant's
     obligations hereunder, shall be deemed to have assumed liability to
     Landlord for all amounts paid to persons other than Landlord by such
     Successors in consideration of any such assignment in violation of the
     provisions hereof. (See Addendum, Section 10).

          (d)  If Tenant is a corporation and if at any time during the Lease
     Term the person or persons who own the voting shares at the time of the
     execution of this Lease cease for any reason, including but not limited to
     merger, consolidation or other reorganization involving another
     corporation, to own a majority of such shares or if Tenant is a partnership
     and if at any time during the Lease Term the general partner or partners
     who own the general partnership interests in the partnership at the time of
     the execution of this Lease, cease for any reason to own a majority of such
     interests (except as the result of transfers by gift, bequest or
     inheritance to or for the benefit of members of the immediate family of
     such original shareholder(s) or partner(s)), such an event shall be deemed
     to be an assignment.  The preceding sentence shall not apply whenever
     Tenant is a corporation the outstanding stock of which is listed on a
     recognized security exchange, or if at least eighty percent (80%) of its
     voting stock is owned by another corporation, the voting stock of which is
     so listed. Notwithstanding the foregoing, Tenant shall have the right to
     add investors, change investors or otherwise change its ownership
     structure, including offering interests in Tenant publicly, and such
     changes shall not be an assignment requiring Landlord's consent so long as
     such changes do not decrease Tenant's financial strength, in Landlord's
     reasonable opinion and as long as Tenant gives Landlord written notice of
     such change in Tenant's structure at least 30 days before such change is
     effective.


                                   -Page 11-
<PAGE>
                                                                    EXHIBIT 10.6


     14.  MECHANIC'S LIENS. Tenant will not permit any mechanic's liens or
other liens to be placed upon the Premises, the Building, or the Property and
nothing in this Lease shall be deemed or construed in any way as constituting
the consent or request of Landlord, express or implied, by inference or
otherwise, to any person for the performance of any labor or the furnishing
of any materials to the Premises, the Building, or the Property or any part
thereof, nor as giving Tenant any right, power, or authority to contract for
or permit the rendering of any services or the furnishing of any materials
that would give rise to any mechanic's or other liens against the Premises,
the Building, or the Property. In the event any such lien is attached to the
Premises, the Building, or the Property, then, in addition to any other right
or remedy of Landlord, Landlord may, but shall not be obligated to, discharge
the same. Any amount paid by Landlord for any of the aforesaid purposes
including, but not limited to, attorneys fees, shall be paid by Tenant to
Landlord promptly on demand as additional rent. In the event Landlord does
consent to the performance of any labor or the furnishing of any materials to
the Premises, the Building, or the Property by any party, which consent must
be in writing, Tenant shall be responsible for insuring that all such persons
procure and maintain insurance coverage against such risks, in such amounts
and with such companies as Landlord may require, including, but not limited
to, Builder's Risk and Worker's Compensation insurance.

     15.  PROPERTY INSURANCE.

          (a)  Landlord shall maintain fire and extended coverage insurance on
     the Building and the Premises in such amounts as Landlord elects. The cost
     of such insurance shall be included as a part of the Basic Costs, and
     payments for losses thereunder shall be made solely to Landlord or the
     mortgagees of Landlord as their interests shall appear.

          (b)  Tenant shall maintain at its expense, in an amount equal to full
     replacement cost, fire and extended coverage insurance on all of its
     personal property, including removable trade fixtures and leasehold and
     tenant improvements, located in the Premises and in such additional amounts
     as are required to meet Tenant's obligations pursuant to Paragraph 19
     hereof. Tenant shall furnish evidence satisfactory to Landlord of the
     maintenance and timely renewal of such insurance, and Tenant shall obtain
     and deliver to Landlord a written obligation on the part of each insurer to
     notify Landlord at least thirty (30) days prior to the modification,
     cancellation or expiration of such insurance policies. In the event Tenant
     shall not have delivered to Landlord a policy or certificate evidencing
     such insurance at least thirty (30) days prior to the expiration date of
     each expiring policy, Landlord may obtain such insurance as Landlord may
     reasonably require to protect Landlord's interest (which obtaining of
     insurance shall not be deemed to be a waiver of Tenant's default
     hereunder). The cost to Landlord of obtaining such policies, plus an
     administrative fee in the amount of fifteen percent (15%) of the cost of
     such policies shall be paid by Tenant to Landlord as additional rent upon
     demand.

          (c)  Landlord and Tenant each hereby waives on behalf of itself and
     its insurers (none of which shall ever be assigned any such claim or be
     entitled thereto due to subrogation or otherwise) any and all rights of
     recovery, claim, action, or cause of action, against the other, its agents,
     officers or employees, for any loss or damage that may occur to the
     Premises, or any improvements thereto or the Building of which the Premises
     are a part, or any improvements thereto, or any personal property of such
     party therein, by reason of fire, the elements, or any other cause(s) which
     are, or could be, insured against under the terms of the standard fire and
     extended coverage insurance policies referred to in this Paragraph 15,
     regardless of whether such insurance is actually maintained and regardless
     of the cause or origin of the damage involved,


                                   -Page 12-
<PAGE>
                                                                    EXHIBIT 10.6


     including sole, joint or concurrent, negligence of the other party hereto,
     its agents, officers, or employees.

     16.  LIABILITY AND WORKER'S COMPENSATION INSURANCE.

          (a)  Tenant and Landlord shall, each at its own expense, maintain
     during the term of this Lease a policy or policies of comprehensive general
     liability insurance (including endorsement or separate policy for owned or
     non-owned automobile liability) with respect to the respective activities
     of each in the Building and on the Property, with the premiums thereon
     fully paid on or before the due date, issued by and binding upon an
     insurance company or companies approved by Landlord. Such insurance shall
     afford minimum protection of not less than $1,000,000.00 per occurrence per
     person coverage for bodily injury, property damage, personal injury, or
     combination thereof. The term "PERSONAL INJURY" herein used means false
     arrest, detention or imprisonment, malicious prosecution, wrongful entry,
     libel and slander. If only a combined single limit coverage is available,
     it shall be for at least $1,000,000.00 per occurrence with an umbrella
     policy of at least $5,000,000.00 combined single limit per occurrence.
     Tenant's insurance policy shall name Landlord as an additional insured and
     shall include coverage for the contractual liability of Tenant to indemnify
     Landlord pursuant to Paragraph 17 of this Lease.

          (b)  Tenant shall obtain and maintain in force worker's compensation
     and employer's liability insurance to cover Tenant's liability to its
     employees to the extent required by law, provided that Tenant shall
     indemnify and hold harmless Landlord, its employees, agents, successors and
     assigns from any and all claims made by Tenant's employees regarding such
     worker's compensation or employer's liability issues.

          (c)  Landlord and Tenant each hereby waives subrogation on its behalf
     and on behalf of its insurer, to the extent subrogation on a paid claim can
     be legally waived prior to loss by contract between the parties, in respect
     of any payment made by such insurer under any liability or worker's
     compensation policy. Neither Landlord nor Tenant shall be liable to the
     other or any insurance company (by way of subrogation or otherwise)
     insuring the other party for any loss or damage to any building, structure
     or other tangible property, or bodily injury or personal injury, or any
     resulting loss of income, or losses from workers' compensation laws and
     benefits, even though such loss or damage might have been occasioned by the
     negligence of such parry, its agents or employees, if any such loss or
     damage is covered by insurance benefitting the party suffering such loss or
     damage or was required to be covered by insurance pursuant to this Lease.

          (d)  Each party shall use its good faith efforts to cause its general
     liability, automobile liability and worker's compensation policies to be
     endorsed by the issuing insurer waiving rights of subrogation of such
     insurer against the other party hereto. The failure of any insurer to issue
     such endorsement shall not be deemed to limit or alter the force and effect
     of Paragraph 16(c) of this Lease.

     17.  INDEMNITY. Neither Landlord nor any of its officers, directors,
employees or agents shall be liable to Tenant, or to Tenant's agents,
servants, employees, customers, licensees, or invitees for any injury to
person or damage to property caused by any act, omission, or neglect of
Tenant, its agents, servants, employees, customers, invitees, licensees or
any other person entering the Building or upon the Property under the
invitation of Tenant or arising out of the use of the Property, Building or
Premises by Tenant and the conduct of its business or out of a default by
Tenant in the performance of its obligations hereunder. Tenant hereby
indemnifies and holds Landlord and its officers, directors, employees and


                                   -Page 13-
<PAGE>
                                                                    EXHIBIT 10.6


agents ("INDEMNITEES"), harmless from all liability and claims for any
property damage, or bodily injury or death of, or personal injury to, a
person in or on the Premises, or at any other place, including the Property
or the Building, caused, in whole or in part, by Tenant, its employees,
agents, servants, customers, invitees or licensees and this indemnity shall
be enforceable to the full extent whether or not such liability and claims
are the result of the sole, joint or concurrent acts, negligent or
intentional, or otherwise, of Tenant, or its employees, agents, servants,
customers, invitees or licensees. Such indemnity for the benefit of
Indemnitees shall be enforceable even if Indemnitees, or any one or more of
them have or has caused or participated in causing such liability and claims
by their joint or concurrent acts, negligent or intentional, or otherwise.
(See Addendum, Section 11).

     18.  EVIDENCE OF INSURANCE. On or before five (5) days following the
date of this Lease, Tenant will cause its insurer(s) to issue and deliver to
Landlord certificate(s) of insurance in the form attached hereto as EXHIBIT
"F" evidencing the existence and coverage of insurance required herein.

     19.  CASUALTY DAMAGE. If the Premises or any part thereof shall be
damaged by fire or other casualty, Tenant shall give prompt written notice
thereof to Landlord. In case the Building shall be so damaged that
substantial alteration or reconstruction of the Building shall, in Landlord's
sole opinion, be required (whether or not the Premises shall have been
damaged by such casualty) or in the event there is less than two (2) years of
the Lease Term remaining or in the event any mortgagee of Landlord's should
require that the insurance proceeds payable as a result of a casualty be
applied to the payment of the mortgage debt or in the event of any material
uninsured loss to the Building, Landlord may, at its option, terminate this
Lease by notifying Tenant in writing of such termination within ninety (90)
days after the date of such casualty. If Landlord does not thus elect to
terminate this Lease, Landlord shall commence and proceed with reasonable
diligence to restore the Building, and the improvements located within the
Premises, if any, for which Landlord had financial responsibility pursuant to
the Work Letter Agreement attached hereto as EXHIBIT "D" (except that
Landlord shall not be responsible for delays not within the control of
Landlord) to substantially the same condition in which it was immediately
prior to the happening of the casualty. Notwithstanding the foregoing,
Landlord's obligation to restore the Budding, and the improvements located
within the Premises, if any, for which Landlord had financial responsibility
pursuant to the Work Letter Agreement, shall not require Landlord to expend
for such repair and restoration work more than the insurance proceeds
actually received by the Landlord as a result of the casualty and Landlord's
obligation to restore shall be further limited so that Landlord shall not be
required to expend for the repair and restoration of the improvements located
within the Premises, if any, for which Landlord had financial responsibility
pursuant to the Work Letter Agreement, more than the dollar amount of the
Allowance, if any, described in the Work Letter Agreement. When the repairs
described in the preceding two sentences have been completed by Landlord,
Tenant shall complete the restoration of all improvements, including
furniture, fixtures and equipment, which are necessary to permit Tenant's
reoccupancy of the Premises which Landlord is not obligated to restore as set
forth above.  Except as set forth above, all cost and expense of
reconstructing the Premises shall be borne by Tenant, and Tenant shall
present Landlord with evidence satisfactory to Landlord of Tenant's ability
to pay such costs prior to Landlord's commencement of repair and restoration
of the Premises. Tenant shall not be entitled to receive any credit or
payment with respect to any portion of the Reconstruction Allowance not
actually spent upon restoration of the Promises. Landlord shall not be liable
for any inconvenience or annoyance to Tenant or injury to the business of
Tenant resulting in any way from such damage or the repair thereof, except
that, subject to the provisions of the next sentence, Landlord shall allow
Tenant a fair diminution of rent during the time and to the extent the
Premises are unfit for occupancy. If the Premises or any other portion of the
Building is damaged by fire or other casualty resulting from the fault or
negligence of Tenant or any of Tenant's agents, employees, or invitees, the
rent hereunder shall not be diminished during the repair of such damage and


                                   -Page 14-
<PAGE>
                                                                    EXHIBIT 10.6


Tenant shall be liable to Landlord for the cost of the repair and restoration
of the Building caused thereby to the extent such cost and expense is not
covered by insurance proceeds.

     20.  DAMAGES FROM CERTAIN CAUSES. Landlord shall not be liable to Tenant
for any injury to person or damage to property sustained by Tenant or any
person claiming through Tenant resulting from any accident or occurrence in
the Premises or any other portion of the Building caused by the Premises or
any other portion of the Building becoming out of repair or by defect in or
failure of equipment, pipes, or wiring, or by broken glass, or by the backing
up of drains, or by gas, water, steam, electricity, or oil leaking, escaping
or flowing into the Premises (except where due to Landlord's willful failure
to make repairs required to be made pursuant to other provisions of this
Lease, after the expiration of a reasonable time after written notice to
Landlord of the need for such repairs), nor shall Landlord be liable to
Tenant for any loss or damage that may be occasioned by or through the acts
or omissions of other tenants of the Building or of any other persons
whomsoever, including, but not limited to riot, strike, insurrection, war,
court order, requisition, order of any governmental body or authority, acts
of God, fire or theft.

     21.  CONDEMNATION. If the whole or any substantial part of the Premises
or if the Building or any portion thereof which would leave the remainder of
the Building unsuitable for use as an office building comparable to its use
on the Commencement Date, shall be taken or condemned for any public or
quasi-public use under governmental law, ordinance or regulation, or by right
of eminent domain, or by private purchase in lieu thereof, then Landlord may,
at its option, terminate this Lease and the rent shall be abated during the
unexpired portion of this Lease, effective when the physical taking of said
Premises or said portion of the Building shall occur. In the event this Lease
is not terminated, the rent for any portion of the Premises so taken or
condemned shall be abated during the unexpired term of this Lease effective
when the physical taking of said portion of the Premises shall occur. All
compensation awarded for any such taking or condemnation, or sale proceeds in
lieu thereof, shall be the property of Landlord, and Tenant shall have no
claim thereto, the same being hereby expressly waived by Tenant, except for
any portions of such award or proceeds which are specifically allocated by
the condemning or purchasing party for the taking of or damage to trade
fixtures of Tenant, which Tenant specifically reserves to itself.

     22.  EVENTS OF DEFAULT/REMEDIES.

          (a)  The following events shall be deemed to be events of default
     under this Lease:

               (i)    Tenant shall fail to pay within five days of the due date
          any Base Rental or other rent payable by Tenant to Landlord under this
          Lease (hereinafter sometimes referred to as a "MONETARY DEFAULT").

               (ii)   Any failure by Tenant (other than a Monetary Default) to
          comply with any term, provision or covenant of this Lease, which
          failure is not cured within twenty (20) days after delivery to Tenant
          of notice of the occurrence of such failure or if such failure is not
          reasonably susceptible of being cured within such twenty (20) day
          period, Tenant shall fail to commence the curing thereof within such
          twenty (20) day period, or having commenced the curing thereof, Tenant
          shall fail to diligently pursue the curing of such default with
          reasonable diligence to completion.

               (iii)  Tenant or any Guarantor shall become insolvent, or shall
          make a transfer in fraud of creditors, or shall commit an act of
          bankruptcy or shall make an assignment


                                   -Page 15-
<PAGE>
                                                                    EXHIBIT 10.6


          for the benefit of creditors, or Tenant or any Guarantor shall admit
          in writing its inability to pay its debts as they become due.

               (iv)   Tenant or any Guarantor shall file a petition under any
          section or chapter of the United States Bankruptcy Code, as amended,
          pertaining to bankruptcy, or under any similar law or statute of the
          United States or any State thereof, or Tenant or any Guarantor shall
          be adjudged bankrupt or insolvent in proceedings filed against Tenant
          or any Guarantor thereunder; or a petition or answer proposing the
          adjudication of Tenant or any Guarantor as a bankrupt or its
          reorganization under any present or future federal or state bankruptcy
          or similar law shall be filed in any court and such petition or answer
          shall not be discharged or denied within sixty (60) days after the
          filing thereof.

               (v)    A receiver or trustee shall be appointed for all or
          substantially all of the assets of Tenant or any Guarantor or of the
          Premises or of any of Tenant's property located thereon in any
          proceeding brought by Tenant or any Guarantor, or any such receiver or
          trustee shall be appointed in any proceeding brought against Tenant or
          any Guarantor and shall not be discharged within sixty (60) days after
          such appointment or Tenant or such Guarantor shall consent to or
          acquiesce in such appointment.

               (vi)   The leasehold estate hereunder shall be taken on
          execution or other process of law in any action against Tenant.

               (vii)  Tenant shall abandon or vacate any substantial portion of
          the Premises without the prior written permission of Landlord for a
          period longer than 365 consecutive days during the Lease Term. If
          Tenant or any other person acting on Tenant's behalf has removed, is
          removing or has made preparations to remove (other than in the normal
          course of business) goods, equipment, fixtures or other property from
          the Premises in amounts substantial enough to indicate a probable
          intent to abandon or vacate the Premises without the prior written
          permission of Landlord, Tenant's abandonment of the Premises shall be
          deemed conclusively established for all purposes. The provisions of
          the foregoing sentence shall supersede the provisions of the Texas
          Property Code.

               (viii) Tenant shall fail to take possession of and occupy the
          Premises within sixty (60) days following the Commencement Date and
          thereafter continuously conduct its operations in the Premises for the
          Permitted Use as set forth in Paragraph 4 hereof.

               (ix)   The liquidation, termination, dissolution, forfeiture of
          right to do business or death of Tenant or any Guarantor.

          (b)  Upon the occurrence of any event or events of default under this
     Lease, whether enumerated in this Paragraph or not, Landlord shall have the
     option to pursue any one or more of the following remedies without any
     notice (except as expressly prescribed herein) or demand for possession
     whatsoever (and without limiting the generality of the foregoing, Tenant
     hereby specifically waives notice and demand for payment of rent or other
     obligations due and waives any and all other notices or demand requirements
     imposed by applicable law):

               (i)    Terminate this Lease, in which event Tenant shall
          immediately surrender the Premises to Landlord. If Tenant fails to
          surrender the Premises upon termination of


                                   -Page 16-
<PAGE>
                                                                    EXHIBIT 10.6


          the Lease hereunder, Landlord may without prejudice to any other
          remedy which it may have for possession or arrearages in rent, enter
          upon and take possession of the Premises and expel or remove Tenant
          and any other person who may be occupying said Premises, or any part
          thereof, by force, if necessary, without being liable for prosecution
          or any claim of damages therefor, and Tenant hereby agrees to pay to
          Landlord on demand the amount of all loss and damage which Landlord
          may suffer by reason of such termination, whether through inability to
          relet the Premises on satisfactory terms or otherwise, specifically
          including but not limited to all Costs of Reletting (hereinafter
          defined) and any deficiency that may arise by reason of any reletting.
          If such termination is caused by the failure to pay rent and/or the
          abandonment of any substantial portion of the Premises, Landlord may
          elect, by sending written notice thereof to Tenant, to receive
          liquidated damages in an amount equal to the Base Rental and other
          rent payable hereunder for the month during which the Lease is
          terminated times the lesser of (A) twelve (12) or (B) the number of
          months remaining in the Lease Term as of the date of such failure to
          pay rent and/or abandonment of any substantial portion of the
          Premises. Such liquidated damages shall be in lieu of the payment of
          loss and damage Landlord may suffer by reason of such termination as
          provided in the preceding sentence but shall not be in lieu of or
          reduce in any way any amount (including accrued rent) or damages due
          to breach of covenant (whether or not liquidated) payable by Tenant to
          Landlord which is accrued and outstanding at the time of the
          termination of the Lease.

               (ii)   Enter upon and take possession of the Premises and expel
          or remove Tenant or any other person who may be occupying said
          Premises, or any part thereof, by force, if necessary, without having
          any civil or criminal liability therefor and without terminating this
          Lease. Landlord may (but shall be under no obligation to) relet the
          Premises or any part thereof for the account of Tenant, in the name of
          Tenant or Landlord or otherwise, without notice to Tenant for such
          term or terms which may be greater or less than the period which would
          otherwise have constituted the balance of the Lease Term and on such
          conditions (which may include concessions or free rent) and for such
          uses as Landlord in its absolute discretion may determine, and
          Landlord may collect and receive any rents payable by reason of such
          reletting. Tenant agrees to pay Landlord on demand all Costs of
          Reletting and any deficiency that may arise by reason of such
          reletting. Landlord shall not be responsible or liable for any failure
          to relet the Premises or any part thereof or for any failure to
          collect any rent due upon any such reletting. No such re-entry or
          taking of possession of the Premises by Landlord shall be construed as
          an election on Landlord's part to terminate this Lease unless a
          written notice of such termination is given to Tenant.

               (iii)  Enter upon the Premises by force if necessary without
          having any civil or criminal liability therefor, and do whatever
          Tenant is obligated to do under the terms of this Lease and Tenant
          agrees to reimburse Landlord on demand for any expense which Landlord
          may incur in thus affecting compliance with Tenant's obligations under
          this Lease together with interest at the lesser of a per annum rate
          equal to (i) the Maximum Rate or (ii) the Prime Rate plus five percent
          (5%) and Tenant further agrees that Landlord shall not be liable for
          any damages resulting to Tenant from such action, whether caused by
          the negligence of Landlord or otherwise.

               (iv)   In order to regain possession of the Premises and to deny
          Tenant access thereto, Landlord or its agent may, at the expense and
          liability of the Tenant, alter or


                                   -Page 17-
<PAGE>
                                                                    EXHIBIT 10.6


          change any or all locks or other security devices controlling access
          to the Premises without posting or giving notice of any kind to
          Tenant. Landlord shall have no obligation to provide Tenant a key or
          grant Tenant access to the Premises so long as Tenant is in default
          under this Lease. Tenant shall not be entitled to recover possession
          of the Premises, terminate this Lease, or recover any actual,
          incidental, consequential, punitive, statutory or other damages or
          award of attorneys' fees, by reason of Landlord's alteration or change
          of any lock or other security device and the resulting exclusion from
          the Premises of the Tenant or Tenant's agents, servants, employees,
          customers, licensees, invitees or any other persons from the Premises.
          Landlord may, without notice, remove and either dispose of or store,
          at Tenant's expense, any property belonging to Tenant that remains in
          the Premises after Landlord has regained possession thereof. Any such
          property of Tenant not retaken by Tenant from Landlord's storage
          within 30 days after removal from the Premises shall, at Landlord's
          option. be deemed conveyed by Tenant to Landlord under this Lease as
          by a bill of sale without further payment or credit by Landlord to
          Tenant. Tenant acknowledges that the provisions of this subparagraph
          of this Lease supersedes die Texas Property Code and Tenant farther
          warrants and represents that it hereby knowingly waives any rights it
          may have thereunder.

               (v)    Terminate this Lease by giving Tenant written notice
          thereof, in which event, Tenant shall pay to Landlord the sum of (i)
          all rent accrued hereunder through the date of termination, (ii) all
          Costs of Reletting, and (iii) an amount equal to (A) the total rent
          that Tenant would have been required to pay for the remainder of the
          Lease Term discounted to present value minus; (B) the then present
          fair rental value of the Premises for such period, similarly
          discounted.

          (c)  For purposes of this Lease, the term "COSTS OF RELETTING" shall
     mean all costs and expenses incurred by Landlord in connection with the
     reletting of the Promises, including without limitation the cost of
     cleaning, renovation, repairs, decoration and alteration of the Premises
     for a new tenant or tenants, advertisement, marketing, brokerage and legal
     fees, the cost of protecting or caring for the Premises while vacant, the
     cost of removing and storing any property located on the Premises, any
     increase in insurance premiums caused by the vacancy of the Premises, costs
     of carrying the Premises such as taxes, insurance premiums, utilities and
     security precautions, any unearned brokerage commissions paid in connection
     with this Lease, parking fees or occupancy taxes due under the Lease,
     reimbursement of any previously waived Base Rental, Basic Costs, free rent,
     or reduced rental rate, and any concession made or paid by Landlord to the
     benefit of Tenant in consideration of this Lease including, but not limited
     to, any moving allowances, contributions or payments by Landlord for tenant
     improvements or build-out allowances, or assumptions by Landlord of any of
     Tenant's previous lease obligations and any other out-of-pocket expenses
     incurred by Landlord including tenant inducements such as the cost of
     moving the new tenant or tenants and the cost of assuming any portion of
     the existing lease(s) of the new tenant(s).

          (d)  Except as otherwise herein provided, no repossession or
     re-entering on the Premises or any part thereof pursuant to Paragraph 22(b)
     hereof or otherwise shall relieve Tenant or any Guarantor of its
     liabilities and obligations hereunder, all of which shall survive such
     repossession or re-entering. Notwithstanding any such repossession or
     re-entering on the Premises or any part thereof by reason of the occurrence
     of an event of default, Tenant will pay to Landlord the Base Rental and
     other rent or other sum required to be paid by Tenant pursuant to this
     Lease.


                                  -Page 18-

<PAGE>
                                                                    EXHIBIT 10.6


          (e)  No right or remedy herein conferred upon or reserved to Landlord
     is intended to be exclusive of any other right or remedy, and each and
     every right and remedy shall be cumulative and in addition to any other
     right or remedy given hereunder or now or hereafter existing by agreement,
     applicable law or in equity.  In addition to other remedies provided in
     this Lease, Landlord shall be entitled, to the extent permitted by
     applicable law, to injunctive relief in case of the violation, or attempted
     or threatened violation, of any of the covenants, agreements, conditions or
     provisions of this Lease, or to a decree compelling performance of any of
     the other covenants, agreements, conditions or provisions of this Lease, or
     to any other remedy allowed to Landlord at law or in equity. Forbearance by
     Landlord to enforce one or more of the remedies herein provided upon an
     event of default shall not be deemed or construed to constitute a waiver of
     such default.

          (f)  This Paragraph 22 shall be enforceable to the maximum extent such
     enforcement is not prohibited by applicable law, and the unenforceability
     of any portion thereof shall not thereby render unenforceable any other
     portion. To the extent any provision of applicable law requires some action
     by Landlord to evidence or effect the termination of this Lease or to
     evidence the termination of Tenant's right of occupancy, Tenant and
     Landlord hereby agree that written notice by Landlord to any of Tenant's
     agents, servants or employees, which specifically sets forth Landlord's
     intention to terminate, shall be sufficient to evidence and effect the
     termination herein provided for.

     23.  TENANT REMEDIES. Except to the extent specifically provided herein,
Tenant shall not have the right to an abatement of rent or to terminate this
Lease as a result of Landlord's default as to any covenant or agreement
contained in this Lease or as a result of the breach of any promise or
inducement in connection herewith, whether in this Lease or elsewhere and Tenant
hereby waives such remedies of abatement of rent and termination. Tenant hereby
agrees that Tenant's remedies for default hereunder or in any way arising
in connection with this Lease including any breach of  any promise or inducement
or warranty, express or implied, shall be limited to:

          (a)  A suit for direct and proximate damages provided that Tenant has
     given the notices as hereinafter required. Notwithstanding anything to the
     contrary contained in this Lease, the liability of Landlord to Tenant for
     any default by Landlord under the terms of this Lease shall be limited to
     the interest of Landlord in the Building and the Property and Tenant agrees
     to look solely to Landlord's interest in the Building and the Property for
     the recovery of any judgment against the Landlord, it being intended that
     Landlord shall not be personally liable for any judgment or deficiency.
     Tenant hereby covenants that, prior to the filing of any suit for direct
     and proximate damages, it shall give Landlord and all mortgagees whom
     Tenant has been notified hold mortgages or deed of trust liens on the
     Property, Building or Premises ("LANDLORD'S MORTGAGEES") notice and
     reasonable time to cure any alleged default by Landlord.

          (b)  In the event Landlord fails to commence the cure of a material
     default of any material covenant or agreement contained in this Lease
     within sixty (60) days following receipt of notice specifying such alleged
     default from Tenant by both Landlord and Landlord's mortgagees, equitable
     abatement of the Base Rental and other rent due hereunder to the extent
     reasonably necessary to adjust for any inconvenience occasioned by
     Landlord's failure to theretofore commence the cure of such default.


                                   -Page 19-
<PAGE>
                                                                    EXHIBIT 10.6


     24.  NO WAIVER. Failure of Landlord to declare any default immediately
upon its occurrence, or delay in taking any action in connection with an
event of default, shall not constitute a waiver of such default, nor shall it
constitute an Estelle against Landlord, but Landlord shall have the right to
declare the default at any time and take such action as is lawful or
authorized under this Lease. Failure by Landlord to enforce its rights with
respect to any one default shall not constitute a waiver of its rights with
respect to any subsequent default. Receipt by Landlord of Tenant's keys to
the Premises shall not constitute an acceptance of surrender of the Premises.

     25.  EVENT OF BANKRUPTCY. In addition to, and in no way limiting the
other remedies set forth herein Landlord and Tenant agree that if Tenant ever
becomes the subject of a voluntary or involuntary bankruptcy, reorganization,
composition, or other similar type proceeding under the federal bankruptcy
laws, as now enacted or hereinafter amended, then:

          (a)  "ADEQUATE PROTECTION" of Landlord's interest in the Premises
     pursuant to the provisions of Section 361 and 363 (or their successor
     sections) of the Bankruptcy Code, 11 U.S. C. Paragraph 101, ET SEQ. (such
     Bankruptcy Code as amended from time to time being herein referred to as
     the "BANKRUPTCY CODE"), prior to assumption and/or assignment of the Lease
     by Tenant shall include, but not be limited to all (or any part) of the
     following:

               (i)    the continued payment by Tenant of the Base Rental and
          all other rent due and owing hereunder and the performance of all
          other covenants and obligations hereunder by Tenant;

               (ii)   the hiring of security guards to protect the Premises if
          Tenant abandons and/or ceases operations; such obligation of Tenant
          only to be effective so long as Tenant remains in possession and
          control of the Premises to the exclusion of Landlord;

               (iii)  the furnishing of an additional/new security deposit by
          Tenant in the amount of three (3) times the then-current monthly Base
          Rental and other rent payable hereunder.

          (b)  "ADEQUATE ASSURANCE OF FUTURE PERFORMANCE" by Tenant and/or any
     assignee of Tenant pursuant to Bankruptcy Code Section 365 will include
     (but not be limited to) payment of an additional/new Security Deposit in
     the amount of three (3) times the then-current Base Rental payable
     hereunder.

          (c)  Any person or entity to which this Lease is assigned pursuant to
     the provisions of the Bankruptcy Code, shall be deemed without further act
     or deed to have assumed all of the obligations of Tenant arising under this
     Lease on and after the effective date of such assignment. Any such assignee
     shall, upon demand by Landlord, execute and deliver to Landlord an
     instrument confirming such assumption of liability.

          (d)  Notwithstanding anything in this Lease to the contrary, all
     amounts payable by Tenant to or on behalf of the Landlord under this Lease,
     whether or not expressly denominated as "rent", shall constitute "rent" for
     the purposes of Section 502(b)(6) of the Bankruptcy Code.

          (e)  If this Lease is assigned to any person or entity pursuant to the
     provisions of the Bankruptcy Code, any and all monies or other
     considerations payable or otherwise to be delivered to Landlord (including
     Base Rentals and other rent hereunder), shall be and remain the


                                   -Page 20-
<PAGE>
                                                                    EXHIBIT 10.6


     exclusive property of Landlord and shall not constitute property of Tenant
     or of the bankruptcy estate of Tenant. Any and all monies or other
     considerations constituting Landlord's property under the preceding
     sentence not paid or delivered to Landlord shall be held in trust by Tenant
     or Tenant's bankruptcy estate for the benefit of Landlord and shall be
     promptly paid to or turned over to Landlord.

          (f)  If Tenant assumes this Lease and proposes to assign the same
     pursuant to the provisions of the Bankruptcy Code to any person or entity
     who shall have made a bona fide offer to accept an assignment of this Lease
     on terms acceptable to the Tenant, then notice of such proposed
     offer/assignment, setting forth (i) the name and address of such person or
     entity; (h) all of the terms and conditions of such offer, and (iii) the
     adequate assurance to be provided Landlord to assure such person's or
     entity's future performance under the Lease, shall be given to Landlord by
     Tenant no later than twenty (20) days after receipt by Tenant, but in any
     event no later than ten (10) days prior to the date that Tenant shall make
     application to a court of competent jurisdiction for authority and approval
     to enter into such assumption and assignment, and Landlord shall thereupon
     have the prior right and option, to be exercised by notice to Tenant given
     at any time prior to the effective date of such proposed assignment, to
     accept an assignment of this Lease upon the same terms and conditions and
     for the same consideration, if any, as the bona fide offer made by such
     persons or entity, less any brokerage commission which may be payable out
     of the consideration to be paid by such person for the assignment of this
     Lease.

          (g)  To the extent permitted by law, Landlord and Tenant agree that
     this Lease is a contract under which applicable law excuses Landlord from
     accepting performance from (or rendering performance to) any person or
     entity other than Tenant within the meaning of Sections 365(c) and
     365(c)(2) of the Bankruptcy Code.

     26.  PEACEFUL ENJOYMENT. Tenant shall, and may peacefully have, hold, and
enjoy the Premises, subject to the other terms hereof, provided that Tenant pays
the rent and other sums herein recited to be paid by Tenant and performs all of
Tenant's covenants and agreements herein contained. This covenant and any and
all other covenants of Landlord shall be binding upon Landlord and its
successors only with respect to breaches occurring during its or their
respective periods of ownership of the Landlord's interest hereunder.

     27.  SUBSTITUTION. [Intentionally Omitted]

     28.  HOLDING OVER. In the event of holding over by Tenant after
expiration or other termination of this Lease or in the event Tenant
continues to occupy the Premises after the termination of Tenant's right of
possession pursuant to Paragraph 22(b) hereof, Tenant shall, throughout the
entire holdover period, pay rent equal to 150% of the sum of the Base Rental
and additional rent which would have been applicable had the term of this
Lease continued through the period of such holding over by Tenant. No holding
over by Tenant or payments of money by Tenant to Landlord after the
expiration of the term of this Lease shall be construed to extend the term of
this Lease or prevent Landlord from recovery of immediate possession of the
Premises by summary proceedings or otherwise unless Landlord has sent written
notice to Tenant that Landlord has elected to extend the term of the Lease.
Tenant shall be liable to Landlord for all damage, including any
consequential damage, which Landlord may suffer by reason of any holding over
by Tenant and Tenant shall indemnify Landlord against any and all claims made
by any other tenant or prospective tenant against Landlord for delay by
Landlord in delivering possession of the Premises to such other tenant or
prospective tenant.


                                   -Page 21-
<PAGE>
                                                                    EXHIBIT 10.6


     29.  SUBORDINATION TO MORTGAGE. Tenant accepts this Lease subject and
subordinate to any mortgage, deed of trust or other lien presently existing
or hereafter arising upon the Premises, or upon the Building and/or the
Property and to any renewals, modifications, refinancings and extensions
thereof. This clause shall be self-operative and no further instrument of
subordination shall be required. However, Tenant agrees upon demand to
execute such further instruments subordinating this Lease or attorning to the
holder of any such liens as Landlord may request. Landlord is hereby
irrevocably vested with full power and authority to subordinate this Lease to
any mortgage, deed of trust or other lien now existing or hereafter placed
upon the Premises, or the Building and/or the Property if Tenant does not
properly execute and return to Landlord the documents required to further
evidence such subordination within ten (10) days after the documents are
delivered to Tenant. The terms of this Lease are subject to approval by the
Landlord's existing Lender(s) and any lender(s) who, at the time of the
execution of this Lease, have committed or are considering committing to
Landlord to make a-loan secured by all or any portion of the Property, and
such approval is a condition precedent to Landlord's obligations hereunder.
In the event that Tenant should fail to execute any subordination or other
agreement required by this Paragraph promptly as requested, Tenant hereby
irrevocably constitutes Landlord as its attorney-in-fact to execute such
instrument in Tenant's name, place and stead, it being agreed that such power
is one coupled with an interest in Landlord and is accordingly irrevocable.
Tenant agrees that it will from time to time upon request by Landlord execute
and deliver to such persons as Landlord shall request a statement in
recordable form certifying that this Lease is unmodified and in full force
and effect (or if there have been modifications, that the same is in full
force and effect as so modified), stating the dates to which rent and other
charges payable under this Lease have been paid, stating that Landlord is not
in default hereunder (or if Tenant alleges a default stating the nature of
such alleged default) and further stating such other matters as Landlord
shall reasonably require. (See Addendum, Section 12).

     30.  ATTORNEY'S FEES. In the event either party defaults in the
performance of any of the terms of this Lease and the other party employs an
attorney in connection therewith, the non-prevailing party agrees to pay the
prevailing party's reasonable attorneys' fees.

     31.  NOTICE. Any notice in this Lease provided for must, unless
otherwise expressly provided herein, be in writing, and may, unless otherwise
in this Lease expressly provided, be given or be served by depositing the
same in the United States mail, postage paid and certified with return
receipt requested, or by prepaid telegram, when appropriate, addressed to the
party to be notified at the address stated in this Lease or such other
address notice of which has been given to the other party or by delivering
the same in person to such party or an officer or partner of such party.
Notice deposited in the mail in the manner hereinabove described shall be
effective as of the date it is so deposited.

     32.  SEVERABILITY. If any term or provision of this Lease, or the
application thereof to any person or circumstance shall, to any extent, be
invalid or unenforceable, the remainder of this Lease, or the application of
such term or provision to persons or circumstances other than those as to
which it is held invalid or unenforceable, shall not be affected thereby, and
each term and provision of this Lease shall be valid and enforced to the
fullest extent permitted by law.

     33.  RECORDATION. Tenant agrees not to record this Lease or any
memorandum hereof.

     34.  GOVERNING LAW. This Lease and the rights and obligations of the
parties hereto shall be interpreted, construed, and enforced in accordance
with the laws of the State of Texas.


                                   -Page 22-
<PAGE>
                                                                    EXHIBIT 10.6


     35.  FORCE MAJEURE. Whenever a period of time is herein prescribed for
the taking of any action by Landlord, Landlord shall not be liable or
responsible for, and there shall be excluded from the computation of such
period of time, any delays due to strikes, riots, acts of God, shortages of
labor or materials, war, governmental laws, regulations or restrictions, or
any other cause whatsoever beyond the control of Landlord.

     36.  TIME OF PERFORMANCE. Except as expressly otherwise herein provided,
with respect to all required acts of Tenant, time is of the essence of this
Lease.

     37.  TRANSFERS BY LANDLORD. Landlord shall have the right to transfer
and assign, in whole or in part, all of its rights and obligations hereunder
and in the Building and Property referred to herein, and in such event and
upon such transfer Landlord shall be released from any further obligations
hereunder, and Tenant agrees to look solely to such successor in interest of
Landlord for the performance of such obligations.

     38.  COMMISSIONS. Landlord and Tenant hereby indemnify and hold each
other harmless against any loss, claim, expense or liability with respect to
any commissions or brokerage fees claimed on account of the execution and/or
renewal of this Lease due to any action of the indemnifying party, except
that Landlord will pay the commissions to the Tenant's broker in accordance
with a separate commission agreement.

     39.  JOINT AND SEVERAL LIABILITY. If there is more than one Tenant, or
if the Tenant as such is comprised of more than one person or entity, the
obligations hereunder imposed upon Tenant shall be joint and several
obligations of all such parties.

     40.  AUTHORITY. In the event Tenant is a corporation (including any form
of professional association), partnership (general or limited), or other form
of organization other than an individual, then each individual executing or
attesting this Lease on behalf of Tenant hereby covenants, warrants and
represents: (i) that such individual is duly authorized to execute or attest
and deliver this Lease on behalf of Tenant in accordance with the
organizational documents of Tenant; (ii) that this Lease is binding upon
Tenant; (iii) that Tenant is duly organized and legally existing in the state
of its organization, and is qualified to do business in the State of Texas;
(iv) that upon request, Tenant will provide Landlord with true and correct
copies of all organizational documents of Tenant. and any amendments thereto;
and (v) that the execution and delivery of this Lease by Tenant will not
result in any breach of, or constitute a default under any mortgage, deed of
trust, lease, loan, credit agreement, partnership agreement or other contract
or instrument to which Tenant is a party or by which Tenant may be bound. If
Tenant is a corporation, Tenant will, prior to the Commencement Date, deliver
to Landlord a copy of a resolution of Tenant's board of directors authorizing
or ratifying the execution and delivery of this Lease, which resolution will
be duly certified to Landlord's satisfaction by the secretary or assistant
secretary of Tenant.

     41.  FINANCIAL CONDITION OF TENANT. Tenant acknowledges that the
financial capability of Tenant to perform its obligations hereunder is
material to Landlord and that Landlord would not enter into this Lease but
for its belief, based on its review of Tenant's financial statements, that
Tenant is capable of performing such financial obligations. Tenant hereby
represents, warrants and certifies to Landlord that its financial statements
are true and correct in all material respects.

     42.  EFFECT OF DELIVERY OF THIS LEASE. Landlord has delivered a copy of
this Lease to Tenant for Tenant's review only, and the delivery hereof does
not constitute an offer to Tenant or option. This


                                   -Page 23-
<PAGE>
                                                                    EXHIBIT 10.6


Lease shall not be effective until an original of this Lease executed by both
Landlord and Tenant and this Lease has been approved by Landlord's mortgagee,
Landlord and Tenant hereby agree that Landlord will be entitled to
immediately endorse and cash Tenant's good faith rent and the Security
Deposit check(s) accompanying this Lease when the Lease is executed by both
Tenant and Landlord. It is further agreed and understood that such action
will not guarantee acceptance of this Lease by Landlord, but, in the event
Landlord does not accept this Lease, such deposits will be refunded in full
to Tenant.

     43.  ENTIRE AGREEMENT. This Lease Agreement, including the following
Exhibits:

          Exhibit A   -  Property Description
          Exhibit B   -  Outline and Location of Premises
          Exhibit C   -  Payment of Excess Basic Cost
          Exhibit D   -  Work Letter Agreement
          Exhibit D-1 -  Building Standard Materials
          Exhibit D-2 -  Tenant Improvement Allowance
          Exhibit E   -  Parking
          Exhibit F   -  Certificate of Insurance for Tenant
          Exhibit G   -  [Intentionally Omitted]
          Exhibit H   -  Rules and Regulations
          Exhibit I   -  Renewal Option
          Addendum
          Roof License Agreement

constitute the entire agreement between the parties hereto with respect to
the subject matter of this Lease. Tenant expressly acknowledges and agrees
that Landlord has not made and is not making, and Tenant, in executing and
delivering this Lease, is not relying upon, any warranties, representations,
promises or statements, except to the extent that the same are expressly set
forth in this Lease. All understandings and agreements heretofore had between
the parties are merged in this Lease which alone fully and completely
expresses the agreement of the parties, neither party relying upon any
statement or representation not embodied in this Lease.

     44.  LANDLORD'S LIEN. In addition to any statutory lien for rent in
Landlord's favor, Landlord (the secured party for purposes hereof) shall have
and Tenant (the debtor for purposes hereof) hereby grants to Landlord,
subject to the last sentence of this paragraph, a continuing security
interest for all Base Rental, rent and other sums of money becoming due
hereunder from Tenant, upon all goods, wares, equipment, fixtures, furniture,
inventory, accounts, contract rights, chattel paper and other personal
property of Tenant situated on the Premises subject to this Lease being
described as Suite 500 of the Building, located in Dallas, Dallas County,
Texas (a description of the property in and upon which the Premises is
located and an outline of the Premises are attached hereto as EXHIBIT "A" and
EXHIBIT "B" respectively), and such property shall not be removed therefrom
without the consent of Landlord until all arrearages in rent as well as any
and all other sums of money then due to Landlord hereunder shall first have
been paid and discharged. Fixtures located at the Premises and products of
collateral are also covered hereby by the filing hereof in the real property
records of Dallas County, Texas. In the event of a default under this Lease,
Landlord shall have, in addition to any other remedies provided herein or by
law, all rights and remedies under the Uniform Commercial Code, including
without limitation the right to sell the property described in this Paragraph
at public or private sale upon ten (10) days notice to Tenant which notice
Tenant hereby agrees is adequate and reasonable. Tenant hereby agrees to
execute such other instruments necessary or desirable in Landlord's
discretion to perfect the security interest hereby created. Any statutory
lien for rent is not hereby waived, the express contractual lien herein


                                   -Page 24-
<PAGE>
                                                                    EXHIBIT 10.6


granted being in addition and supplementary thereto. Landlord and Tenant
agree that this Lease and the security interest granted herein serve as a
financing statement and a copy or photographic or other reproduction of this
Paragraph of this Lease may be filed of record by Landlord and have the same
force and effect as the original. Tenant warrants and represents that the
collateral subject to the security interest granted herein is not purchased
or used by Tenant for personal, family or household purposes. Tenant further
warrants and represents to Landlord that the lien granted herein constitutes
a first and superior lien and that Tenant will not allow the placing of any
other lien upon any of the property described in this Paragraph without the
prior written consent of Landlord. Record owner of the Premises is 14850
Quorum Associates, Ltd. Tenant/Debtor's address is 14850 QUORUM DRIVE, SUITE
500, DALLAS, TEXAS 75240 and Landlord/Secured Party's address is C/O LEHMAN
BROTHERS, 3 WORLD FINANCIAL CENTER, 29TH FLOOR, NEW YORK, NY 10285. Landlord,
on a case-by case basis, not as a blanket waiver of lien, will subordinate
the landlord's lien granted in this paragraph to the lien of Tenant's lending
institution on any furniture, fixtures or equipment after Landlord is
presented proper documentation of that lending institution's lien on said
furniture, fixtures and equipment.

     IN WITNESS WHEREOF, Landlord and Tenant have executed this Lease in
multiple original  counterparts as of the day and year first above written.

                                       LANDLORD:

                                       14850 Quorum Associates, Ltd.

                                       By:  Commercial Properties 3, L.P.
                                            a Virginia limited partnership,
                                            General Partner

                                       By:  Real Estate Services VII, Inc.,
                                            a Delaware corporation,
                                            General Partner


                                       By:  /s/  LAWRENCE M. OSTOW
                                            ---------------------------------
                                            Lawrence M. Ostow
                                            Vice President

                                       TENANT:

                                       ObjectSpace, Inc.



                                       By:  /s/  JOHN W. PRITCHETT
                                            ---------------------------------
                                            Name:   John W. Pritchett
                                                 ----------------------------
                                            Title:   Chief Financial Officer
                                                  ---------------------------


                                   -Page 25-

<PAGE>
                                                                    EXHIBIT 10.6


                                    EXHIBIT "A"

                             PROPERTY DESCRIPTION

Being a 1.753 acre tract of land out of the Josiah Pancoast Survey, Abstract
No. 11466, and the G.W. Fisher Survey, Abstract No. 482, Dallas County, Texas
and being out of Quorum, a 71.90 acre addition to the City of Addison as
recorded in Volume 79100, Page 1895, Plat Records, Dallas County, Texas, and
being a portion of the property conveyed by Daon-Texas to Quorum Investors,
#2, Ltd., by deed filed July 22, 1980, in Volume 80144, Page 764, Deed
Records, Dallas County, Texas, said 1.753 acre tract being more particularly
described as follows:

COMMENCING at a point, said point being the southeast comer of Block 1 of
said Quorum Addition also being the intersection of the west right-of-way
line of Dallas Parkway (200 foot R.O.W.) with the north right-of-way line of
Quorum Drive (variable R.O.W.);

THENCE N 01 DEG. 39' 54" along said west right-of-way line of Dallas Parkway
a distance of 501.93 feet to a point;

THENCE S 89 DEG. 46' 47" W a distance of 197.56 feet to the POINT OF
BEGINNING for this tract;

THENCE South a distance of 145.82 feet to a point for comer;

THENCE West a distance of 178.00 feet to a point for comer;

THENCE South for a distance of 146.00 feet to a point for comer;

THENCE 79 DEG. 31' 38" W for a distance of 198.79 feet to an X cut in
concrete for a comer being a point in the east line of said Quorum Drive and
being a point of curvature of a curve to the right having a radius of 235.01
feet, a tangent of 37.82 feet and an internal angle of 18 DEG. 17' 06";

THENCE along said curve to the right and being the east right-of-way line of
said Quorum Drive for an are distance of 75.00 feet to an iron rod and the
point of tenancy of said curve;

THENCE N 14 DEG. 18' E along said cast side line of Quorum Drive for a
distance of 260.49 feet to an iron rod for comer;

THENCE N 89 DEG. 46' 47" E a distance of 302.39 feet to the POINT OF
BEGINNING;

CONTAINING 76,349.98 net square feet or 1.753 acres of land.


                                   -Page 26-
<PAGE>
                                                                    EXHIBIT 10.6


                                    EXHIBIT "B"

                          OUTLINE AND LOCATION OF PREMISES


                     (Plan showing Tenant's space at Suite 500
                    of approximately 18,251 rentable square feet)

                     (Plan showing Tenant's space at Suite 400
                    of approximately 7,009 rentable square feet)



                                   -Page 27-

<PAGE>
                                                                    EXHIBIT 10.6



                                    EXHIBIT "C"

                           PAYMENT OF EXCESS BASIC COSTS

     The Base Rental payable hereunder shall be adjusted upward from time to
time in accordance with the following provisions:

     1.   Tenant's Base Rental is based, in part, upon an Expense Base (herein
so called) equal to the actual per square foot operating expenses for the
Building for calendar year 1997, grossed up to reflect ninety-five percent (95%)
occupancy for the Building. Basic Costs will be calculated in years subsequent
to 1997 in a manner consistent with industry standards with the gross-up
consistently applied in all years so that increases in Basic Costs will result
solely from increases and not from different methods of calculation unless a
change in method of calculation is to more accurately meet industry standards.
Tenant shall, during the Lease Term, pay as an adjustment to Base Rental
hereunder an amount (per each square foot of Rentable Area within the Premises)
equal to the excess ("Excess"), if any, from time to time of actual Basic Costs
per square foot per year for the Rentable Area in the Building over the Expense
Base. Prior to January 1 of each calendar year during Tenant's occupancy or as
soon thereafter as practical, Landlord shall make a good faith estimate of the
Excess for each upcoming calendar year and, upon prior written notice to Tenant,
may require the monthly payment of Base Rental to be adjusted in accordance with
such estimate. Landlord shall have the right from time to time during any such
calendar year to revise the estimate of the Excess for such year and provide
Tenant with a revised statement therefor, and thereafter the amount Tenant shall
pay each month shall be based upon such revised estimate. Any amounts paid based
on any estimate shall be subject to adjustment pursuant to Paragraph 2 below
when actual Basic Costs are available for such calendar year.

     2.   As soon as is practical following the end of each calendar year during
Tenant's occupancy Landlord shall furnish to Tenant a statement of Landlord's
actual Basic Costs for the previous calendar year. If for any calendar year
additional Base Rental collected for the prior year, as a result of Landlord's
estimate of Basic Costs, is in excess of the additional Base Rental actually due
during such prior year, then Landlord shall refund to Tenant any overpayment (or
at Landlord's option, apply such amount against rentals due or to become due
hereunder). Likewise, Tenant shall pay to Landlord, on demand, any underpayment
with respect to the prior year whether or not the Lease has terminated prior to
receipt by Tenant of a statement for such underpayment.

     3.   Tenant, at its expense, shall have the right no more frequently than
once per calendar year, within 90 days after receipt by Tenant of each
applicable annual reconciliation of Basic Costs, following thirty (30) days
prior written notice to Landlord, to audit Landlord's books and records relating
to Basic Costs at Landlord's office during Normal Business Hours.

     4.   "Basic Costs" shall mean all direct and indirect costs and expenses
incurred in each calendar year in connection with operating, maintaining,
repairing, managing and owning the Building and the Property, including, without
limitation, the following:

          (a)  All labor costs for Landlord's employees performing services
     required or utilized in connection with the operation, repair and
     maintenance of and control of access to the Building and the Property,
     including but not limited to amounts incurred for wages, salaries and other
     compensation for services, payroll, social security, unemployment and other
     similar taxes, workmen's compensation insurance, disability benefits,
     pensions, hospitalization, and retirement plans and group insurance.


                                   -Page 28-
<PAGE>
                                                                    EXHIBIT 10.6


          (b)  All management fees, the cost of maintaining a management office
     at the Building, and all fees for legal and accounting services relating to
     the Building and the Property.

          (c)  All rental and/or purchase costs of materials, supplies, hand
     tools and equipment used in the operation, repair, replacement and
     maintenance and the control of access to the Building and the Property.

          (d)  All amounts charged to Landlord by contractors and/or suppliers
     for services, materials, equipment and supplies furnished in connection
     with the operation, repair, maintenance, replacement of and control of
     access to any part of the Building, the plazas, the garage, and the
     sidewalks adjoining the Building, if any, or the Property generally, and
     the heating, air conditioning, ventilating, plumbing, electrical, elevator
     and other systems of the Building and the garage.

          (e)  All premiums paid by Landlord for fire and extended coverage
     insurance, earthquake and extended coverage insurance, liability and
     extended coverage insurance and other insurance customarily carried from
     time to time by lessors of comparable office buildings or required to be
     carried by Landlord.

          (f)  Charges for all utilities including but not limited to water,
     sewer and electricity, but excluding those charges for which tenants are
     individually responsible.

          (g)  Taxes, including (i) all real estate taxes and assessments on the
     Property, the Building or the Premises, and taxes and assessments levied in
     substitution or supplementation in whole or in part of such taxes, (ii) all
     personal property taxes for the Building's personal property, including
     license expenses, (iii) all taxes imposed on services of Landlord's agents
     and employees, and (iv) all other taxes, fees or assessments now or
     hereafter levied by any governmental authority on the Property, the
     Building or its contents or on the operation and use thereof (except as
     relate to specific tenants), but excluding income taxes.

          (h)  All landscape expenses and costs of repairing, resurfacing and
     striping of the parking areas of the Property.

          (i)  Cost of all maintenance service agreements for equipment, alarm
     service, window cleaning, drapery or venetian blind cleaning, janitorial
     services, pest control, uniform supply, landscaping, and parking equipment.

          (j)  Cost of all other repairs, replacements and general maintenance
     of the Property and Building neither specified above nor directly billed to
     tenants.

          (k)  Amortization on a straight-line basis of all capital improvements
     or repairs made to the Building or parking garage subsequent to the
     Commencement Date which are primarily for the purpose of reducing
     operating. expense costs or otherwise improving the operating efficiency of
     the Building or which are required to comply with any change in the laws,
     rules or regulations of any governmental authority or which will extend the
     life of the Building, the cost of such items to be amortized over their
     actual, estimated useful life, but for a period of at least five (5) years.


                                   -Page 29-
<PAGE>
                                                                    EXHIBIT 10.6


          (l)  Operating Costs of the Exterior Common Areas. "Exterior Common
     Areas" shall mean those areas of the Property which are not located within
     the Building and its immediate proximity and which are provided and
     maintained for the common use and benefit of Landlord and tenants of the
     Building generally and the employees, invitees and licensees of Landlord
     and such tenants, including, without limitation, sidewalks and landscapes.

Basic Costs shall not include (i) the cost of capital improvements (except as
above set forth), (ii) depreciation, (iii) interest, (iv) lease commissions, (v)
principal payments on mortgage and other non-operating debts of Landlord, (vi)
costs of repairs, restoration, replacements or other work occasioned by the
exercise by a governmental authority of the right of eminent domain; (vii)
attorneys' fees, costs, disbursements and other expenses incurred in connection
with negotiations or disputes with tenants, prospective tenants, management
agents, purchasers or mortgagees of the Building; (viii) allowances, concessions
and other costs and expenses incurred in completing, renovating or otherwise
improving, decorating or redecorating space for tenants, or prospective tenants,
or vacant, leasable space in the Building; (ix) any cost that should be
capitalized in accordance with generally accepted accounting principals except
non-structural capital improvements made to reduce operating expenses in an
annual amortization over the actual useful life with a reasonable salvage value,
not to exceed the actual cost savings, and non-structural capital improvements
made by Landlord to comply with changes in laws after the date hereof, amortized
on a straight line basis over the actual useful life; (x) rental payments made
under any ground or underlying lease or leases; (xi) costs incurred in
connection with the sale, financing, refinancing, mortgaging, selling or change
of ownership of the Building; (xii) costs or expenses of utilities directly
metered to tenants of the Building and payable separately by such tenants and
costs of additional electrical equipment installed in premises of other tenants
of the Building; (xiii) costs of repairs, restoration, replacements or other
work occasioned by the gross negligence or intentional tort of Landlord, or any
representative, employee, agent or affiliate of Landlord; (xiv) costs of
repairing, replacing or otherwise correcting defects in construction of the
Building, the Tenant Improvements, the leasehold improvements of other tenants
of the Building, or in the Building equipment; (xv) costs or expenses relating
to another tenant's space, which were incurred in rendering any service or
benefit to such tenant that Landlord was not required, or were for a service in
excess of the service that Landlord was required, to provide Tenant hereunder;
and (xvi) costs of Landlord's general corporate overhead and general
administrative expenses, organizational fees, and partnership expenses.

     5.   Notwithstanding any language in the Lease seemingly to the contrary,
if the Building is not fully occupied during any calendar year of the Lease
Term, actual Basic Costs and the Excess for purposes of this Exhibit "C" shall
be determined as if the Building had been ninety-five percent (95%) occupied
during such year. This paragraph does not apply in any way to the ninety-five
percent (95 %) provision in Paragraph I hereof.


                                   -Page 30-

<PAGE>
                                                                    EXHIBIT 10.6


                                    EXHIBIT "D"

                               WORK LETTER AGREEMENT

     This Work Letter Agreement supplements and is hereby incorporated in that
certain lease (hereinafter referred to as the "LEASE") dated and executed
concurrently herewith by and between 14850 QUORUM ASSOCIATES, LTD. (hereinafter
referred to as "LANDLORD") and OBJECTSPACE, INC., a Texas corporation
(hereinafter referred to as "Tenant") with the terms defined in the Lease to
have the same definition where used herein.

     1.   The Premises are leased to Tenant in their "AS IS" condition and this
Work Letter Agreement is intended to set forth the obligations of Landlord and
Tenant with respect to the preparation of the Premises for Tenant's occupancy.
All improvements described in this Work Letter Agreement to be constructed in
and upon the Premises are hereinafter referred to as the "Tenant Improvements."
It is agreed that construction of the Tenant Improvements will be completed in
accordance with the procedures set forth in this Work Letter Agreement.

     2.   Tenant shall devote such time in consultation with Landlord or
Landlord's agent as may be required to provide all necessary information to
Landlord or Landlord's agent as Landlord deems necessary in order to enable
Landlord to complete, and obtain Tenant's written approval of, the final layout,
drawings, and plans for the Premises. If Tenant fails to furnish any such
information on or before June 13, 1997 or fails to approve layout, drawings or
plans within five (5) Business Days after written request, Tenant agrees to pay
on demand all costs and expenses and increased unit prices incurred by Landlord
on account of Tenant's failure to furnish such information and approved drawings
within such prescribed times and any scheduled dates for completion of the
Tenant Improvements shall be extended day-for-day for the delay caused by
Tenant. All of Tenant's plans and specifications shall be subject to Landlord's
consent, the granting or denial of which shall be in Landlord's sole discretion.

     3.   Space planning and construction drawings, and when deemed necessary by
Landlord, engineering drawings, shall be prepared by Landlord's architect or
designer. Landlord shall bear the cost of the initial space planning drawings,
to include one revision, which shall be prepared by Landlord's architect or
designer. Unless otherwise provided in EXHIBIT "D-2", Tenant shall pay for
additional space planning services beyond those specified above, for Landlord's
standard construction and engineering drawings covering Landlord's Building
Standard materials as defined in EXHIBIT "D-1", and for any nonstandard
construction and engineering drawings, or any additional costs for drawings
occasioned by special installation other than Building Standard. Tenant may pay
for services out of the Allowance, if any, provided in EXHIBIT "D-2". Tenant
shall furthermore be responsible for the design, function and maintenance of all
special improvements, whether installed by Landlord at Tenant's request or
installed by Tenant with Landlord's prior written approval. Tenant shall use the
Building Standard materials unless other materials are expressly approved in
writing by Landlord.

     4.   Prior to commencing any construction of Tenant Improvements, Landlord
shall submit to Tenant a written estimate setting for the anticipated cost of
the Tenant Improvements (excluding any costs which may be specified herein or in
EXHIBIT "D-2" as being borne by Landlord), including but not limited to labor
and materials, contractor's fees (whether paid to independent contractors or the
five percent (5%) fee charged by Landlord for acting as a general contractor),
permit fees, and space planning, construction, and engineering drawing costs
which are the responsibility of Tenant. Within five (5) Business Days Tenant
shall either notify Landlord in writing of its approval of the cost estimate, or
specify its objections thereto and desired changes to the proposed Tenant


                                  -Page 31-
<PAGE>
                                                                    EXHIBIT 10.6


Improvements. In the event Tenant notifies Landlord of such objections and
desired changes, Tenant shall work with Landlord to reach acceptable plans and
cost estimate; provided, however, if Tenant fails to give written approval of
a cost estimate within ten (10) Business Days following delivery to Tenant of
the original cost estimate, Tenant shall be chargeable with one day of Delay
for each day thereafter until Tenant provides to Landlord in writing its
approval of a cost estimate.

     5.   In the event Landlord's estimate and/or the actual cost of
construction shall exceed the Allowance, (as defined in EXHIBIT "D-2" attached
hereto), if any (such amounts exceeding the Allowance being herein referred to
as the "EXCESS COSTS"), Tenant shall pay to Landlord such Excess Costs as
follows:

          (a)  Tenant shall deliver to Landlord, with its approval of the
     Landlord's estimate, and in any event prior to commencement of
     construction, an amount equal to fifty percent (50%) of the Excess Costs as
     then estimated by Landlord.

          (b)  After substantial completion of the Tenant Improvements, but
     prior to occupancy of the Premises by Tenant, Tenant shall pay to Landlord
     on demand an amount which when added to the initial payment described in
     subparagraph (a) above equals ninety percent (90%) of the Excess Costs as
     then estimated by Landlord.

          (c)  As soon as the final accounting can be prepared and submitted to
     Tenant, Tenant shall pay on demand to Landlord the entire balance of the
     Excess Costs based upon the actual cost of construction.

     The statements of costs submitted by Landlord's contractors shall be
     conclusive for purposes of determining the actual cost of the items
     described therein. The amounts payable hereunder constitute other rent
     payable pursuant to the Lease, and the failure to timely pay same
     constitutes an event of default under the Lease.

     6.   If Tenant shall request any change, addition or alteration in the
working drawings, after approval by Landlord and Tenant, Landlord shall have
such working drawings prepared, and Tenant shall promptly reimburse Landlord for
the cost thereof. Promptly upon completion of the revisions, Landlord shall
notify Tenant in writing of the cost which will be chargeable to Tenant by
reason of such change, addition or deletion. Tenant shall, within three (3)
Business Days, notify Landlord in writing whether it desires to proceed with
such change, addition or deletion. In the absence of such written authorization,
Landlord shall have the option to continue work on the Premises disregarding the
requested change, addition or alteration, or Landlord may elect to discontinue
work on the Premises, in which event Tenant shall be chargeable with a Delay in
completion of the Premises resulting therefrom in accordance with Paragraph 3(a)
of the Lease. In the event such revisions result in a higher estimate of the
cost of construction, Tenant shall pay to Landlord an amount sufficient to
provide Landlord with the above described fifty percent (50%) (or if applicable
ninety percent (90%)) payment toward Excess Costs.

     7.   Following approval of the plans and the payment by Tenant of the
required portion of the Excess Costs, if any, Landlord shall cause the Tenant
Improvements to be constructed in accordance with the approved plans. Unless
otherwise specifically provided in the approved plans, all material used in the
construction of the Tenant's Improvements shall be of such quality as determined
by the Landlord's architect or designer, but at least shall be of Building
Standard quality. Landlord shall notify Tenant of substantial completion of the
Tenant Improvements.

                                  -Page 32-
<PAGE>
                                                                    EXHIBIT 10.6


     8.   Any changes to Tenant's plans and specifications required by any
governing Authority to conform to local, state or federal laws will be at the
sole cost of Tenant, in addition to any other previously agreed upon improvement
costs.

     9.   Prior to the commencement of construction of the Tenant Improvements,
Tenant shall provide Landlord the Improvement Letter of Credit.

     10.  Tenant's Allowance (as defined in Exhibit D-2) also shall be applied
to the costs of permits and fees paid to the City of Addison and a management
fee of five percent (5%) of the total amount of the Tenant Improvements to
compensate Landlord's agent for managing the construction of the Tenant
Improvements and assisting in getting appropriate permits.

     11.  Any other language in this Exhibit D notwithstanding, the Tenant
Improvements shall be constructed by one of the twenty general contractors
previously approved by Landlord or by one general contractor of Tenant's choice,
provided that this latter contractor meets the insurance and reference
requirements of Landlord. A minimum of three bids to construct the Tenant
Improvements will be received. Tenant shall have the right to review the bids
and be involved with Landlord in the selection of the general contractor to
perform the work.

     12.  Tenant shall have the option to utilize any items currently in place
in the Premises.

     13.  In the event The Staubach Company acts as a project manager on behalf
of Tenant, any cost of that service may be paid from the Allowance or may be
paid by Tenant directly.

                                     -Page 33-
<PAGE>
                                                                    EXHIBIT 10.6


                                   EXHIBIT "D-1"

     13.  The BUILDING STANDARD (herein so called) materials are the following,
which will be new or in a condition approved by Tenant:

<TABLE>
          <S>                           <C>
          A.   FLOORING:                Grade and quality of carpeting to be
                                        selected by Landlord, with color to be
                                        selected by Tenant from those offered by
                                        Landlord.

          B.   WINDOW COVERING:         Miniblinds or drapes in Landlord's
                                        uniform color.

          C.   CEILING:                 Acoustical tiles - Grid system.

          D.   PARTITIONS:              Sheetrock partitions with tape, bed,
                                        texture and paint finish, and/or vinyl
                                        pre-clad sheetrock.

          E.   DOORS:                   Solid core door with metal frame and
                                        hardware.

          F.   ELECTRICAL POWER:        Standard 110 volt duplex wall-outlets:
                                        mounted convenience outlets.

          G.   LIGHT SWITCHES:          Single pole light switches.

          H.   TELEPHONE FACILITIES:    Standard unwired telephone outlets (ring
                                        and string) mounted on partitions.
                                        Tenant must make timely arrangements for
                                        telephone installation and is
                                        responsible for all charges related to
                                        such installation.

          I.   LIGHT FIXTURES:          Recessed fluorescent lighting fixtures.
</TABLE>

                                    -Page 34-
<PAGE>
                                                                    EXHIBIT 10.6


                                 EXHIBIT "D-2"

Landlord agrees to provide Tenant an allowance (the "ALLOWANCE") of $9.00 per
square foot of Rentable Area in the Premises (which for purposes hereof is
agreed to be 25,260 square feet), being the total sum of $227,340.00 toward the
cost of the Tenant Improvements. Tenant shall not be entitled to any credit for
any amount not applied to the cost of the Tenant Improvements. In the event the
Allowance shall not be sufficient to complete the improvements contemplated by
the approved plans, Tenant shall pay the Excess Costs as prescribed in EXHIBIT
"D".

Tenant shall be able to receive a portion of the Allowance to reimburse Tenant
for Tenant's cost of telephone and data cabling, moving into the Premises and
space planning and construction document preparation. Landlord shall pay Tenant
the amount allocated to those expenses within 30 days after receipt by Landlord
of Tenant's paid invoices therefor.

As part of the initial Tenant Improvements only, Tenant shall be allowed to
amortize over the Lease Term at 12% per annum, an ADDITIONAL allowance for
Tenant Improvements of $5.00 per square foot of Rentable Area, being the total
sum of $126,300.00, provided that Landlord approves Tenant's financial
statements before the beginning of any Tenant Improvements to which this
additional allowance shall be applied. The amortized payments of this additional
sum shall be part of the Base Rental due under the Lease, except in the last
year of the Lease Term, during which year Tenant shall continue to make payments
of the amortized amount, any other provision of the Lease notwithstanding.

                                     -Page 35-
<PAGE>
                                                                    EXHIBIT 10.6


                                  EXHIBIT "E"

                                    PARKING

     Landlord shall make available to Tenant during of the term of this Lease
the use of 76 of the Building's parking spaces (the "SPACES") in the Building
parking garage (the "PARKING GARAGE") on an unreserved basis. The number of
Spaces may be reduced if city ordinances or other laws require the reduction.
Tenant shall not use more Spaces than designated above without the prior written
consent of Landlord. There shall be no charge to Tenant for use of the Spaces
during the initial Lease Term. If this Lease is renewed or if the Premises are
expanded, Tenant shall be charged for the then Spaces based on current market
charges for such parking spaces.

     It is hereby agreed and understood that Landlord's sole obligation
hereunder is to make the Spaces available to Tenant. Tenant's right to the use
of such Spaces shall be subject to compliance with the rules and regulations
promulgated from time to time by the manager of such Parking Garage, and shall
be subject to termination for violation of any such rules or regulations upon
notice from such manager. Landlord shall have no liability whatsoever for any
property damage, loss or theft and/or personal injury which might occur as a
result of or in connection with the use of the Spaces by Tenant, its employees,
agents, servants, customers, invitees and licensees, and Tenant hereby agrees to
indemnify and hold Landlord harmless from and against any and all costs, claims,
expenses, and/or causes of action which Landlord may incur in connection with or
arising out of Tenant's use of the Spaces. The failure, for any reason, of
Landlord to provide or make available the Spaces to Tenant or the inability of
Tenant to utilize these Spaces shall under no circumstances be deemed a default
by Landlord pursuant to the terms of the Lease or give rise to any claim or
cause of action by Tenant against Landlord, the same being hereby expressly
waived by Tenant.

                                     -Page 36-
<PAGE>
                                                                    EXHIBIT 10.6


                                    EXHIBIT "F"

                         CERTIFICATE OF INSURANCE FOR TENANT








                                   [CERTIFICATE]

<PAGE>
                                                                    EXHIBIT 10.6


                                    EXHIBIT "H"

                           BUILDING RULES AND REGULATIONS

The following rules and regulations shall apply, where applicable, to all leased
premises, the Building, the parking garage associated therewith, the land
situated beneath the Building and the appurtenances thereto.  Tenant will
faithfully observe and comply with these Rules and Regulations attached to the
Lease.  Landlord will not be responsible to Tenant for the noncompliance with
any of the Rules and Regulations by any other tenant or occupant of the
Building.

     1.   Sidewalks, doorways, vestibules, halls, stairways and other similar
areas shall not be obstructed by Tenant or used by any Tenant for any purpose
other than ingress and egress to and from the leased premises and for going from
one to another part of the Building.  At no time shall Tenant, its agents or
employees store any items in the Common Areas of the Building or elsewhere on
the Property.

     2.   Plumbing, fixtures and appliances shall be used only for the purposes
for which designed, and no sweepings, rubbish, rags or other unsuitable material
shall be thrown or placed therein.  Damage resulting to any such fixtures or
appliances from misuse by a Tenant or such Tenant's agents, employees or
invitees, shall be paid by such Tenant, and Landlord shall not in any case be
responsible therefor.

     3.   No signs, advertisements or notices shall be painted or affixed on or
to any windows, doors or other parts of such Building except those of such
color, size, style and in such places as shall be first approved in writing by
Landlord.  No nails, hooks or screws shall be driven or inserted in any part of
the Building except by the Building maintenance personnel nor shall any part of
the Building be defaced by Tenants.  No curtains or other window treatments
shall be placed between the glass and the Building standard window treatment.

     4.   Landlord will provide and maintain an alphabetical directory board for
all Tenants in the first floor (main lobby) of the Building and no other
directory shall be permitted unless previously consented to by Landlord in
writing.

     5.   Landlord shall provide all locks for doors in each Tenant's leased
premises, at the cost of such Tenant, and no Tenant shall place any additional
lock or locks on any door in its leased area without Landlord's prior written
consent.  A reasonable number of keys to the locks on the doors in each Tenant's
leased premises shall be furnished by Landlord to each Tenant, at the cost of
such Tenant (which cost shall be Landlord's cost plus a fifteen percent (15%)
administrative fee), and the Tenant shall not have any duplicate keys made.

     6.   All Tenants will refer all contractors, contractors representatives
and installation technicians to Landlord for Landlord's supervision, approval
and control before the performance of any contractual services.  This provision
shall apply to all work performed in the Building including, but not limited to
installations of telephones, telegraph equipment, electrical devices and
attachments, doors, entranceways, and any and all installations of every nature
affecting floors, walls, woodwork, trim windows, ceilings, equipment and any
other physical portion of the Building.

     7.   Movement in or out of the Building of furniture, office equipment,
safes, heavy equipment, bulky material, merchandise or materials which require
the use of elevators or stairways, or movements through the Building entrances
or lobby shall be restricted to such hours as Landlord shall



                                   -Page 38-

<PAGE>
                                                                    EXHIBIT 10.6


designate.  All such movement shall be under the supervision of Landlord and
shall proceed in a manner agreed upon between the Tenants and Landlord by
prearrangement before performance so as to arrive at the optimum time, method
and routing of such movement; subject, however, to Landlord's decision and
control, to prohibit any such article from being brought into the Building
for safety or other concerns. The Tenants are to assume all risks as to the
damage to articles moved and injury to persons or public engaged or not
engaged in such movement, including equipment, property and personnel of
Landlord if damaged or injured as a result of acts in connection with
carrying out this service for a Tenant from the time of entering the property
to completion of work; and Landlord shall not be liable for acts of any
person engaged in, or any damage or loss to any of said property or persons
resulting from, any act in connection with such service performed for a
Tenant.

     8.   Landlord shall have the power to prescribe the weight and position of
safes and other heavy equipment or items which shall in all cases, to distribute
weight, stand on supporting devices approved by Landlord.  All damages done to
the Building by the installation or removal of any property of a Tenant, or done
by a Tenant'' property while in the Building, shall be repaired at the expense
of such Tenant.

     9.   Corridor doors, when not in use, shall be kept closed.

     10.  Each Tenant shall cooperate with Landlord's employees in keeping its
leased premises neat and clean.  Tenants shall not employ any person for the
purpose of such cleaning other than the Building's cleaning and maintenance
personnel.  Nothing shall be swept or thrown into the corridors, halls, elevator
shafts or stairways.

     11.  To ensure orderly operation of the Building, no ice, mineral or other
water, towels, newspapers, etc. shall be delivered to any leased area except by
persons appointed or approved by Landlord in writing.

     12.  Should a Tenant require telegraphic, telephonic, annunciator or other
communication service, Landlord will direct the electrician where and how wires
are to be introduced and placed and none shall be introduced or placed except as
Landlord shall direct. Electric current shall not be used for power or heating
without Landlord's prior written permission.

     13.  Tenant shall not make or permit any improper, objectionable or
unpleasant noises or odors in the Building or otherwise interfere in any way
with other Tenants or persons having business with them. No food shall be
prepared in or distributed from the Premises without prior written approval of
the manager of the Building.

     14.  No birds or animals shall be brought into or kept in, on or about any
Tenant's leased premises.

     15.  No inflammable or explosive fluid or substance shall be used or kept
in the Building.

     16.  No portion of any Tenant's leased premises shall at any time be used
or occupied as sleeping or lodging quarters; nor shall they be used for immoral
or illegal purposes, including but not limited to, the manufacture or sale of
liquor, narcotics or other drugs in any form.

     17.  Tenant shall not cause, maintain or permit any outside storage on or
about the Premises or Property.


                                   -Page 39-

<PAGE>
                                                                    EXHIBIT 10.6


     18.  Electrical space heaters and fans are not allowed in the Building.
Tenant shall comply with all emergency and safety procedures established by
Landlord, the Addison Fire Department, and/or any other governmental agency
having jurisdiction over the Building including, without limitation,
participation in periodic drills, familiarization with emergency procedures and
the designation of individuals who shall be responsible for the implementation
of emergency action. Landlord has the right to evacuate the Building in the
event of an emergency or catastrophe.

     19.  Tenant shall place solid pads under all rolling chairs.

     20.  Tenant agrees to cooperate and assist Landlord in the prevention of
canvassing, soliciting, and peddling within the Building. Said activities are
prohibited in the Building and on the Property at all times.

     21.  Tenant shall, before leaving the Premises unattended, close and lock
outside doors, turn off lights, coffee pots, and other office equipment. Damage
resulting from failure to do so shall be the sole responsibility of and shall be
paid for by Tenant. Landlord will not be responsible for lost or stolen
property, equipment, money or any article taken from the Premises, regardless of
how or when loss occurs.

     22.  Landlord reserves the right to rescind any of the rules and
regulations and to make such other and further rules and regulations as in its
judgement shall from time to time be needful for the safety, protection, care
and cleanliness of the Building, the operation thereof, the preservation of good
order therein and the protection and comfort of the Tenants and their agents,
employees, licensees and invitees, which rules and regulations, when made and
written notice thereof is given to a Tenant, shall be binding upon it in like
manner as if originally herein prescribed.


                                   -Page 40-

<PAGE>
                                                                    EXHIBIT 10.6


                                     EXHIBIT "I"

                                    RENEWAL OPTION

     Provided that no event of default has ever occurred under any term or
provision contained in this Lease and no condition exists which with the passage
of time or the giving of notice or both would constitute an event of default
pursuant to this Lease and provided that Tenant has continuously occupied the
Premises for the Permitted Use during the Lease Term, Tenant (but not any
assignee or subtenant) shall have the right and option (the "RENEWAL OPTION") to
renew this Lease, by written notice delivered to Landlord no later than nine (9)
months prior to the expiration of the initial Lease Term, for an additional term
(the "RENEWAL TERM") of sixty (60) months under the same terms, conditions and
covenants contained in the Lease, except that (a) no abatements or other
concessions, if any, applicable to the initial Lease Term shall apply to the
Renewal Term; (b) the Base Rental shall be equal to the market rate for
comparable office space located in the Building as of the end of the initial
Lease Term as determined by Landlord giving consideration to market allowances
and concessions for renewal tenants; (c) a new base year for the "EXPENSE BASE"
referenced in the Lease shall be established; (d) Tenant shall have no option to
renew this Lease beyond the expiration of the Renewal Term; and (e) all
leasehold improvements within the Premises shall be provided in their then
existing condition (on an "as is" basis) at the time the Renewal Term commences.
Failure by Tenant to notify Landlord in writing of Tenant's election to exercise
the Renewal Option herein granted within the time limits set forth for such
exercise shall constitute a waiver of such Renewal Option. In the event Tenant
elects to exercise the Renewal Option as set forth above, Landlord shall, within
thirty (30) days thereafter, notify Tenant in writing of the proposed rental for
the Renewal Term (the "PROPOSED RENEWAL RENTAL"). Tenant shall within thirty (N)
days following delivery of the Proposed Renewal Rental by Landlord notify
Landlord in writing of the acceptance or rejection of the Proposed Renewal
Rental. If Tenant accepts Landlord's proposal, then the Proposed Renewal Rental
shall be the rental rate in effect during the Renewal Term. Failure of Tenant to
respond in writing during the aforementioned thirty (30) day period shall be
deemed an acceptance by Tenant of the Proposed Renewal Rental. Should Tenant
reject Landlord's Proposed Renewal Rental during such thirty (30) day period,
then Landlord and Tenant shall negotiate during the thirty (30) day period
commencing upon Tenant's rejection of Landlord's Proposed Renewal Rental to
determine the rental for the Renewal Term. In the event Landlord and Tenant are
unable to agree to a rental for the Renewal Term during said thirty (30) day
period, then the Renewal Option shall terminate and be null and void and the
Lease shall, pursuant to its terms and provisions, terminate at the end of the
original Lease Term.

     Upon exercise of the Renewal Option by Tenant and subject to the conditions
set forth hereinabove, the Lease shall be extended for the period of such
Renewal Term without the necessity of the execution of any further instrument or
document, although if requested by either party, Landlord and Tenant shall enter
into a written agreement modifying and supplementing the Lease in accordance
with the provisions hereof. Any termination of the Lease during the initial
Lease Term shall terminate all renewal rights hereunder. The renewal rights of
Tenant hereunder shall not be severable from the Lease, nor may such rights be
assigned or otherwise conveyed in connection with any permitted assignment of
the Lease. Landlord's consent to any assignment of the Lease shall not be
construed as allowing an assignment of such rights to any assignee.


                                   -Page 41-

<PAGE>
                                                                    EXHIBIT 10.6


                                      ADDENDUM

This Addendum is to be attached to and made a part of that certain office Lease
(the "LEASE") dated May 30, 1997, between 14850 Quorum Associates, Ltd.
("LANDLORD") and ObjectSpace, Inc. ("TENANT"). All capitalized items used but
not expressly defined in this Addendum shall have the meanings assigned to them
in the body of the Lease. The provisions of this Addendum shall control if in
conflict with any of the foregoing provisions of the Lease.

1.   AREA DETERMINATIONS. The useable and rentable area of the Premises and the
Building and Tenant's Pro Rata Share shall be determined in accordance with
BOMA. Tenant shall have the right from time to time to independently confirm the
rentable and useable area square footage calculations at its own expense.  As
Tenant is given this latter right prior to execution of the Lease, Tenant shall
have no claims against Landlord whatsoever regarding the accuracy of the
rentable and usable areas of the Premises and the Building. (See Lease, Section
1[h]).

2.   CONSTRUCTION DELAY. No Delay shall result from contractor's delay or from
acts beyond the reasonable control of Tenant. Tenant's changes in plans and
specifications shall be deemed to cause a Delay only if Delay actually results.
(See Lease, Section 3[a]).

3.   SUBSTANTIAL COMPLETION. The substantial completion of the Premises shall
not occur until a certificate of occupancy has been issued for all of the
Premises, the punch list consists of matters that can be completed in 30 days or
less and do not interfere with Tenant's use and occupancy of the Premises, and
Tenant, acting reasonably, can make full use of the Premises for the purposes
intended. (See Lease, Section 3[a]).

4.   TERMINATION. If the Commencement Date does not occur by September 1, 1997
for reasons other than Delay, Tenant shall have the right to terminate this
Lease. (See Lease, Section 1[e]).

5.   PERMITTED USE. Tenant's permitted use shall include non-commercial kitchen
and eating facilities, computer and telecommunications facilities, data
processing and transmission, including rooftop satellite communications,
accounting facilities, conference and meeting facilities, copying facilities,
and other uses typically made (and to be hereafter made) by other office tenants
in the Dallas/Ft. Worth metropolitan area. Tenant shall be permitted to have
vending machines. Tenant's intended use of the Premises shall not increase
applicable insurance premiums. (See Lease, Section 4).

6.   SECURITY SERVICES. Tenant shall be provided access to the Premises
twenty-four hours a day, seven days a week. Tenant also shall have the right, at
its sole cost and expense, to install and operate such additional access control
systems as it shall determine for the purpose of limiting access to or within
the Premises as long as Landlord is given access to those control systems
twenty-four hours a day, seven days a week.  (See Lease, Section 7[g]).

7.   SIGNAGE. Tenant shall be entitled to directory listings in the elevator
lobby and signage on the floor on which the Premises are located, at Tenant's
expense, but the cost of such signage may be deducted from the Allowance (as
defined in Exhibit D-2). Tenant shall have the exclusive right to exterior
signage at top of Building and non-exclusive right to Signage on Building
monument signs. Signage on multi-tenant floor shall be Building Standard
graphics. Signage on single tenant floor and exterior of Building need not be
Building Standard but must be approved by Landlord, which approval shall not be
unreasonably withheld. (See Lease, Section 9).


                                   -Page 42-

<PAGE>
                                                                    EXHIBIT 10.6


8.   LANDLORD'S MAINTENANCE. With the exception of maintenance required of
Tenant elsewhere in the Lease, Landlord shall maintain the Building, all
structural components thereof, all base building improvements, all mechanical,
electrical, and plumbing facilities, all utilities, all parking areas, and all
common areas in a good, workmanlike condition comparable to other buildings of
similar quality in the Dallas, Texas metropolitan area. (See Lease, Section 7).

9.   ELECTRICAL CAPACITY. Electrical capacity shall be available to the Premises
without additional charge to Tenant sufficient for (a) low voltage capacity
(120/208 volts) for up to 5 watts per square foot of rentable area to operate
machines of low voltage electrical consumption, such as typewriters,
calculators, photocopiers, telecommunication equipment, desktop and stand alone
and network computers and word processors, and (b) high voltage capacity
(277/480 volts) for up to 2 watts per square foot of rentable area to operate
fluorescent lighting and equipment of high voltage electrical consumption.
Tenant shall have the right to submeter electrical usage in which event Basic
Costs shall exclude electrical source and Tenant shall pay the cost of
electrical service reflected by the submeter. (See Lease, Section 7[d]).

10.  ASSIGNMENT AND SUBLETTING. The language of Section 13(c) of the Lease
notwithstanding, in the event, of a sublease or assignment of the Lease which
generates rental payments greater than Tenant's then existing total monthly
monetary obligations to Landlord, Tenant shall pay to Landlord the excess
consideration received by Tenant after Tenant has deducted its reasonable costs
incurred in securing a permitted subtenant or assignee, which costs may include
marketing, legal, brokerage, and improvements required to secure subtenant or
assignee, together with the cost of any Tenant Improvements that may have been
paid for directly by Tenant, provided Tenant provides Landlord reasonable proof
of the cost of the sums deducted prior to payment of the excess amount to
Landlord. Tenant shall provide Landlord the accountings for Tenant's referenced
costs and the payments of excess rent within 15 days after Tenant receives each
rental payment from the assignee or subtenant. (See Lease, Section 13[c]).

1l.  LANDLORD'S ACTS. Tenant shall not be obligated to indemnify Landlord
against, and Tenant does not waive any claims arising out of, Landlord's gross
negligence or willful misconduct. Landlord will indemnify and hold Tenant
harmless from and against any claims, losses, demands, liabilities, damages, and
expenses (including legal fees) caused solely by the gross negligence or willful
misconduct of Landlord, its agents, servants, and employees. (See Lease, Section
17).

12.  NON-DISTURBANCE. If this Lease shall become subordinate to any mortgage,
ground lease, or master lease, Landlord shall use reasonable efforts to obtain a
non-disturbance agreement regarding Tenant. (See Lease, Section 29).

13.  ROOF ACCESS. Tenant shall be provided access to the roof of the Building to
install a satellite dish and communications equipment as set forth in the Roof
License Agreement which is attached as part of this Lease.


                                   -Page 43-

<PAGE>
                                                                    EXHIBIT 10.6


                                ROOF LICENSE AGREEMENT

THIS ROOF LICENSE AGREEMENT made as of this 30th day of May, 1997, between 14850
Quorum Associates, Ltd. ("LICENSOR") and Objectspace, Inc., a Texas Corporation
("LICENSEE"), having an address at 14850 Quorum Drive, Suites 400 and 500,
Dallas, Texas 75240.

                                      WITNESSETH

Licensor or its predecessor in interest, and Licensee or its predecessor in
interest, have heretofore entered into that certain lease dated May 30, 1997,
for the premises described as Suite Nos. 400 and 500, initially containing
approximately 25, 260 rentable square feet (the "LEASE") in the property
("PROPERTY") known as Quorum II, located at 14850 Quorum Drive, Dallas, Dallas
County, Texas, 75240 which lease has been amended by instruments dated:   None

     A.   BASIC TERMS.  The following terms shall have the following meanings
          throughout this Agreement.

     1.   PROPERTY NAME:      Quorum II

     2.   PROPERTY ADDRESS:   14850 Quorum Drive, Dallas, Texas  75240

     3.   PREMISES:           The space at the Property comprising a portion of
     the roof area of the Property shown on the drawing attached hereto as
     EXHIBIT A ("PREMISES") and which Licensor reserves the right to reasonably
     revise or relocate at any time.

     4.   TERM:               Commencing on July 1, 1997 and ending on March 31,
     2003, subject to amendment, or earlier termination by agreement of the
     parties.

     5.   TYPE OF ACTIVITY AND PURPOSE.  Location for Licensee's satellite dish
     or communication equipment which shall be installed in a location
     designated by Licensor and the cable from such dish or communications
     equipment shall enter the building at the point designated by Licensor.

     B.   LICENSE.  Licensor hereby licenses to Licensee, on a non-exclusive
     basis, the use of the Premises for the Term set forth above, unless
     terminated sooner in accordance herewith, subject to the terms and
     conditions hereof.

     C.   TERMS AND CONDITIONS.  In consideration of the license granted to
     Licensee herein, Licensee agrees to the following:

          1.   PURPOSE.  Licensee shall use the Premises only for the Type of
               Activity and Purpose set forth above and for no other purpose.

          2.   INSURANCE.  Licensee shall ensure that the insurance provisions
               of the above described Lease, by and between 14850 Quorum
               Associates, Ltd. ("LANDLORD") and ObjectSpace, Inc., a Texas
               Corporation ("TENANT"), are extended tot he premises described in
               this license Agreement.

          3.   WAIVER OF CLAIMS AND INDEMNITY.  To the extent not prohibited by
               law, Licensee shall indemnify, defend and save harmless Licensor
               and its partners,


                                   -Page 44-

<PAGE>
                                                                    EXHIBIT 10.6


               beneficiaries, trustees, officers, directors, employees and
               agents, from and against any and all liability, claims,
               damages, costs and expenses, including without limitation,
               attorney's fees, resulting from or in connection with
               Licensee's use and occupancy of the Roof Premises unless
               caused by the gross negligence or willful misconduct of
               Licensor or Licensor's agent.  To the extent not prohibited by
               law, Licensee waives all claims against Licensor and its
               partners, beneficiaries, trustees, officers, directors,
               employees and agents for injury to persons, damage to property
               or to any other interests of Licensee sustained by Licensee or
               any person claiming through Licensee resulting from any
               occurrence in or upon the Premises or the Property.  Without
               limitation, all of Licensee's personal property which may at
               any time be at the Premises shall be at Licensee's sole risk
               unless damage to said personal property of Licensee is caused
               by the gross negligence or willful misconduct of Licensor or
               its agents.

          4.   COSTS OF LITIGATION.  If Licensor or its agents shall without
               fault on their part be made a party to any litigation rising out
               of any act or omission of Licensee, Licensee shall pay all cost
               and expenses, including attorney's fees, incurred by said parties
               on account of said litigation. In the event of any litigation
               between parties of this Agreement, the prevailing party shall be
               entitled to recover from the unsuccessful party its reasonable
               attorney's fees and costs as part of the judgment.

          5.   RELOCATION, POSTPONEMENT AND EARLY TERMINATION. The location of
               the satellite dish or communications equipment on the Premises
               shall be shown on the plans submitted to Licensor for its
               approval. In the event that Licensee desires to move the
               satellite dish or communications equipment to a different place
               on the Premises, then new plans showing such new locations must
               be submitted to Licensor for its approval. Licensee must give
               Licensor at least ten (10) days notice of relocation. All costs
               of such relocation shall be borne by Licensee. Licensor may
               terminate the License granted herein upon a violation by Licensee
               of any provision hereof or of the Lease after the notice and cure
               period provided in the Lease.

          6.   REMOVAL OF PROPERTY; HOLDING OVER. Prior to the end of the Term
               of this license, Licensee shall remove all of its satellite dish
               and communications equipment from the Premises and shall leave
               the Premises in a clean condition and in as good or better
               condition as when Licensee took possession of the Premises,
               making any necessary repairs to the roof or the building. For
               each day or part of a day after the end of the Term that Licensee
               shall have failed to do the foregoing, Licensee shall pay the
               Licensor Two Hundred Dollars ($200.00). If Licensee fails to
               remove its satellite dish and communications equipment by the end
               of the Term, Licensor may take possession of said satellite dish
               and communications equipment and dispose of said satellite dish
               and communications equipment in such lawful manner as it shall
               determine.

          7.   ASSIGNMENT. This Agreement is personal to Licensee. Licensee
               shall not assign, sublicense or in any other manner transfer or
               encumber this Agreement or Licensee's rights hereunder, by
               operation of law or otherwise, except under the


                                   -Page 45-

<PAGE>
                                                                    EXHIBIT 10.6


               same terms and conditions as Tenant may transfer all the Premises
               under the Lease.

          8.   INSPECTION.  Licensor reserves the right to inspect the Premises
               at any time, and to enter the same for any other reasonable
               cause, including without limitation, the making of repairs to the
               Building or grounds.

          9.   OPERATION. Licensee shall operate, maintain and repair the
               Premises, and any communications equipment affixed thereto, for
               the activity and purpose described above during normal business
               hours, unless Licensor shall agree otherwise in writing. If
               Licensee shall fail to so operate, Landlord may declare Tenant in
               default under the Lease after complying with the notice
               provisions of Section 23 (a)(ii) of the Lease (without limiting
               Licensor's remedies for other breaches of this Agreement).

          10.  RULES.   Licensee shall comply with each of the Rules set forth
               on Exhibit "D" of the Lease which are incorporated herein by
               reference and made a part hereof for all purposes. Licensee shall
               also comply with any additional Rules or modifications of the
               Rules that Licensor reasonably may promulgate and notify Licensee
               after the date hereof.

          11.  COMPLIANCE WITH LAWS. Licensee shall at Licensee's sole cost and
               expense install,  operate, maintain and remove the satellite dish
               and communications equipment in accordance with all governmental
               laws, rules, regulations, codes and ordinances and shall obtain
               all FCC, FAA and other governmental licenses, permits and
               approvals required to install, operate, maintain and remove the
               satellite dish and communications equipment.


                                   -Page 46-

<PAGE>
                                                                    EXHIBIT 10.6


     IN WITNESS WHEREOF, the parties have executed this Roof License Agreement
as of the day and year first above written.

                              LICENSOR:

                              14850 Quorum Associates, Ltd., a Texas Limited
                              Partnership

                              By:    Commercial Properties 3, L.P.
                                     a Virginia limited partnership, General
                                     Partner

                              By:    Real Estate Services VII, Inc.,
                                     a Delaware corporation, General Partner

                              By:    /s/ LAWRENCE M. OSTOW
                                     -----------------------------------------
                                     Lawrence M. Ostow
                                     Vice President



                              LICENSEE:

                              ObjectSpace, Inc., a Texas Corporation

                              By:    /s/ JOHN W. PRITCHETT
                                     -----------------------------------------
                              Name:  John W. Pritchett
                                     -----------------------------------------
                              Title: Chief Financial Officer
                                     -----------------------------------------


                                   -Page 47-