Exhibit 10.12


                                    SUBLEASE

1.       PARTIES

         This Sublease ("Sublease"),  dated for -reference purposes only January
16,  1997,  is  entered  into  between  ICF  Kaiser  Engineers,  Inc.,  an  Ohio
corporation ("ICF"), and Forte Software, Inc., a Delaware corporation ("Forte").

2.       DEMISE OF SUBLEASE PREMISES

         2.1 ICF Kaiser Engineers,  Inc., an Ohio corporation,  and the State of
California Public Employees  Retirement System, a Unit of the State and Consumer
Services Agency of the State of California  ("Landlord"),  successor-in-interest
to 1800 Harrison Limited Partnership,  a Texas limited partnership,  are parties
to an  Amended  And  Restated  Lease  Agreement  dated as of July 1,  1988  (the
"Restated  Lease"),  as modified  and  supplemented  by Amendment to Amended and
Restated Lease Agreement dated March 27, 1991,  Second  Amendment to Lease dated
June 30, .1992,  and Third Amendment to Lease dated April 27, 1993. The Restated
Lease,  as so amended,  is referred to in this  Sublease as the " ICF Lease".  A
true  and  complete  copy of the ICF  Lease is  attached  as  Exhibit  1 to this
Sublease.

         2.2 The ICF Lease  demises  to ICF  certain  premises  in the  building
commonly known as 1800 Harrison Street,  Oakland,  California (the  "Building").
ICF desires to sublet a portion of the premises,  as more  particularly  defined
below (tile  "Sublease  Premises") to Forte,  and Forte also desires to take and
sublease the Sublease Premises.

         2.3 Forte also  occupies  office  space in the  Building  pursuant to a
Lease with Landlord dated December 1, 1994 (the "Forte Lease").,.

         2.4      [Reserved]

         2.5 In consideration of these facts and the mutual covenants of ICF and
Forte, and for other valuable  consideration.  ICF hereby sublets and demises to
Forte,  and Forte hereby takes and hires from 1CF, the Sublease  Premises on and
subject to the terms, covenants, and conditions set forth in this Sublease.

3.       DEFINITIONS

         3.1 As used in this  Sublease,  the  following  terms  shall  have  the
meanings given in this Paragraph 3. 1:

         "ICF Kaiser Engineers, Inc.", herein referred to as "ICF".

                  "Affiliate"   means  (i)  a  company  which   controls  or  is
controlled  by a Party or is under  common  control  with a Party,  or (ii) is a
successor  by merger  or  consolidation  to a Party,  or (iii)  acquires  all or
substantially  all of the  assets of a Party as a going  concern  at a time when
such Party is not in default under this Sublease.

                  "Building"  means the  25-story  office  tower  identified  in
Paragraph 2.1 above and the related  Parking  Garage,  all as more  particularly
described in the ICF Lease.

                  "Base Rent" means the amounts  payable  pursuant to Paragraphs
7.1 and 7.2.

                  "Building"  means the  25-story  office  tower  identified  in
Paragraph 2.1 above and the related  Parking  Garage,  all as more  particularly
described in the ICF Lease.

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         "Commencement Date" means January 1, 1997.

                  "Forte Lease" has the meaning given in Paragraph 2.3,

         "ICF Lease" has the meaning given in Paragraph 2.1 above-
         "Initial Alterations" has the meaning given in Paragraph 10. 1.

                  "Landlord's  Consent and Agreement" means that certain Consent
to Sublease  and  Nondisturbance,  Recognition  and  Attornment  Agreement to be
executed by Forte,  ICF, and Landlord in the form  attached as Exhibit 2 to this
Sublease-

         "Lease" means either the ICF Lease or the Forte Lease, depending on the
context in which such word is used.

         "Operating  Expenses" means with respect to the Sublease Premises those
items defined in the ICF Lease as "Basic Costs."

         "Party"  means each of ICF and Forte and the  authorized  assignees  of
each of them, and "Parties" refers to both of them.

                  "Phase One" means the first phase of Forte's  occupancy of the
Sublease Space beginning on the  Commencement  Date and continuing until January
31,  1998,;  and "Phase One Space" means that portion of the Sublease  Premises,
located  on the  7th  Floor  and  consisting  of a  significant  portion  of the
northeast and southeast quadrants of such Floor, containing approximately 16,636
square feet of Net Rentable Area, as depicted on Exhibit 4 to this Sublease. The
subleased premises shall include a pro rata portion of ICF's basement storage at
a rate of $0.675 per square foot per month.

                  "Phase Two" means the second phase of Forte's occupancy of the
Sublease Space beginning  February1,  1998, and continuing  until June 30, 2000;
and "Phase Two Space" means (i) that portion of the Sublease Premises located on
the 7th Floor,  consisting  of the  remaining  Net Rentable  Area of such Floor,
containing  approximately  22,066  square feet of Net Rentab1e Area and (ii) the
entire 6th Floor  containing  approximately  38,702  square feet of Net Rentable
Area.  The Phase Two Space shall  include all of ICF's  basement  storage  space
(2,500  square feet of Net  Rentable  Area),  at $0.675 per square  foot/month..
During Phase Two, Forte shall continue to occupy the Phase One Space.

                  "Rent"  means all  amounts  due from  Forte to ICF under  this
Sublease including,  without  limitation,  Base Rent,  Operating  Expenses,  and
Taxes.

                  "Sublease"  means this  Sublease and all exhibits  referred to
herein and attached to this Sublease, which are incorporated herein by reference
as if set forth in full and made a part of this Sublease.

                  "Sublease  Date"  means the date upon which this  Sublease  is
fully executed by the Parties and all  contingencies  to its  effectiveness  are
satisfied.

                  "Sublease Premises" means these portions of the Building which
Forte is entitled to possess pursuant to this Sublease.

                  "Sublease Term" has the meaning given in Paragraph 6.1.

                  "Taxes" means: (i) with respect to the Sublease Premises those
items defined in the ICF Lease as "Tax Expenses."

         3.2  Capitalized  words  and  phrases  used  in this  Sublease  and not
otherwise  defined  herein shall have the  meanings  given them in the ICF Lease
where applicable to the Sublease Premises.

4.       DELIVERY OF PREMISES

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         4.1 ICF shall  deliver to Forte  possession  of the  Sublease  Premises
according to the following schedule:

                  4.1.1  ICF  shall  deliver  the  Phase  One  Space to Forte on
January 1, 1997.

                  4.1.2.  ICF  shall  deliver  the  Phase  Two Space to Forte on
February 1, 1998.

         4.2      [Reserved]

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5.       CONDITION OF PREMISES UPON DELIVERY

         5.1 At the time ICF delivers  possession of any portion of the Sublease
Premises  to Forte (i) ICF shall  have  removed  all  personal  property,  trade
fixtures,  and equipment owned or controlled by ICF, and shall have repaired all
damage to the Sublease Premises  occurring in connection with such removal,  and
(ii) the  Sublease  Premises  shall be in a clean,  functioning  order  with all
Building systems serving the Sublease  Premises in proper  operating  condition.
Subject  to ICF's  compliance  with the  covenants  contained  in the  preceding
sentence,  and without  waiving or otherwise  limiting  Forte's right to rely on
ICF's representations and warranties elsewhere in this Sublease, Forte agrees to
accept  possession of the Sublease  Premises in the same  condition as exists on
the Sublease Date, "AS IS", and "WITH ALL FAULTS," and ICF shall have no duty to
alter or otherwise  improve the  Sublease  Premises  prior to Forte's  occupancy
under this Sublease.

         5.2      [Reserved]

         5.3      [Reserved]

         5.4      ICF  represents  and  warrants  with  respect to the  Sublease
Premises that:

                  (a) The Sublease  Premises are now, and on the date possession
is to be  delivered  under this  Sublease  the  Sublease  Premises  shall be, in
compliance with all municipal, county, state, federal and other applicable laws,
ordinances, and regulations  (collectively,  "Laws"), governing or pertaining to
the Sublease  Premises (but without regard to any change in the use or occupancy
of the Sublease Premises or alterations or improvements  thereto occurring after
the delivery of  possession  hereunder to Forte under this Sublease or any other
sublease prior to the Commencement Date).

                  (b) The Sublease  Premises,  and all  elements,  systems,  and
equipment serving the Sublease Premises, have been maintained in accordance with
the requirements imposed on ICF by the ICF Lease.

         5.5      [Reserved]

6.       SUBLEASE TERM

         6.1 The term of this Sublease (the "Sublease  Term") shall begin on the
Commencement  Date and shall expire on June 30, 2000. If the  commencement  date
has not occurred by January 15, 1997,  Forte may thereafter  upon ten (10) day's
prior  written  notice  to ICF  terminate  this  sublease  and  all  rights  and
obligations of the parties hereunder.


7.       BASE RENT

         7.1  Beginning on the  Commencement  Date,  Forte shall pay to ICF Base
Rent on the first day of each  calendar  month  during  the  Sublease  Term,  in
advance and without prior notice, set off or demand,  other than as permitted by
this Sublease. as follows:

                  7.1.1 During Phase One the Base Rent shall be Thirty  Thousand
Seven Hundred Seventy-Six and 60/100's Dollars  ($30,776.60) per month. Plus any
storage space occupied.

                  7.1.2.  During  Phase Two,  the Base Rent shall be One Hundred
Forty Four Thousand Eight Hundred Eighty-four and 90/10's Dollars  ($144,884.90)
per month. This includes the basement storage space.

         7.2  Notwithstanding  anything to the contrary in this Agreement,  upon
any default by ICF of its obligations hereunder,  at Forte's option upon written
notice to ICF, Forte may pay Base Rent and other amounts owed herein directly to
Landlord for the account of ICF.

         7.3      [Reserved]

         7.4 Upon  execution of the Sublease,  Forte shall deposit the amount of
Thirty  Thousand Seven Hundred  Seventy Six and 60/100's  Dollars  ($30,776.60),
with ICF as Trustee of the Security 

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Deposit.  Said Deposit  shall be held in a  non-interest-bearing  account  which
shall be held as security during the Sublease Term for the faithful  performance
by Forte of its obligations under this Sublease  including,  but not limited to,
payment of rent. As the Sublease Premises increase during Phase Two, so will the
amount of the  deposit;  the total  deposit  shall be  increased  to One Hundred
Fourteen Thousand One Hundred Eight and 30/100th's Dollars  ($114,108.30),  upon
the  commencement  of Phase Two on  February 1, 1998..  Upon  expiration  of the
Sublease,  ICF shall promptly return the deposited funds to Forte provided Forte
is not in default under the Sublease.

         7.5 If the  Commencement  Date or any other day upon which  Forte is to
commence paying Base Rent for an element of the Sublease Premises is a day other
than the first day of a calendar  month, or if the Sublease Term with respect to
a portion of the  Sublease  Premises  ends on a day other than the last day of a
calendar  month,  the Base Rent for such Sublease  Premises during such calendar
month shall be prorated based upon a thirty (30) day month.

         7.6 Base Rent and all other Rent shall be paid in immediately available
funds to the same place as is set forth below for the delivery of notices to ICF
subject, however, to Forte's right to pay Rent directly to Landlord as permitted
in Section 7.2.

8.       OPERATING EXPENSES AND TAXES

         8.1 Forte shall pay to ICF (or  directly to Landlord for the account of
ICF as permitted in Section 7.2), Operating Expenses as follows:

                  8.1.1 No Operating  Expenses or Taxes shall be payable for the
Sublease Premises during Phase One.

                  8.1.2.  During  Phase  Two,  Forte  shall  pay  the  Operating
Expenses  and Taxes for the  Sublease  Premises as follows:  Forte shall pay the
Operating  Expenses  and Taxes on the  Phase One Space  which are in excess of a
1997 Base Year and Forte shall pay the Operating Expenses and Taxes on the Phase
Two Space which are in excess of a 1998 Base Year.

         8.2      [Reserved]

         8.3 In  determining  the Operating  Expenses and Taxes payable by Forte
hereunder, Landlord's statement of Operating Expenses and Taxes shall be used as
the basis for such calculations.  However,  ICF agrees,  upon written request by
Forte,  to  exercise  such  audit  rights as may be granted to ICF under the ICF
Lease and to contest any  discrepancy  in  Landlord's  statements  of  Operating
Expenses or Taxes disclosed by such audit by appropriate means. Reasonable costs
of such audit or contest  shall be borne by the  Parties  in  proportion  to the
benefit derived by each of them  therefrom,  or shall be borne by Forte if there
is no benefit to such audit or contest.

         8.4 Forte shall  reimburse  ICF within  thirty (30) days after  written
notice (accompanied by a copy of Landlord's invoice and satisfactory evidence of
payment by ICF),  for any  amounts  paid to the  Landlord  as a  consequence  of
services provided to the Sublease Premises,  or the acceleration of depreciation
of building systems which are in excess of that typically provided to tenants of
the Building and for which  Landlord  retains a right to  separately  charge ICF
under  the  ICF  Lease.  Such  additional   charges  may  be  imposed  only  for
extraordinary electrical,  heating, ventilating, and air conditioning, and other
Building services, with no overhead or mark-up beyond what is due Landlord under
the ICF Lease.

9.       ASSIGNMENT AND SUBLETTING

         9.1 Forte may assign its rights and interests  under this Sublease,  or
further sublet all or a portion of the Sublease  Premises  occupied by Forte, to
an Affiliate of Forte,  provided (i) notice of such  assignment or subletting is
given to ICF at least  thirty (30) days in advance of the  effective  date,  and
(ii) any  consent or  approval  of  Landlord  required by the ICF Lease is first
obtained.

         9.2 Where Forte desires to assign this Sublease,  or further sublet all
or any  part of the  Sublease  Premises  to a person  or  entity  other  than an
Affiliate,  Forte shall first  obtain the written  consent of ICF.  Such consent
shall not be unreasonably withheld. However, ICF may reasonably withhold consent
under this Paragraph 9.2 where Landlord's consent also is required under the ICF
Lease and  Landlord  fails or refuses  to give such  consent  (although  nothing
herein  shall  relieve  Landlord of  liability  for failure to give such consent
where the same is required by the ICF Lease).

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<PAGE>

         9.3 If the  ICF  Lease  imposes  a right  of  recapture  or a right  of
Landlord to obtain or participate in any consideration received in excess of the
Rent  payable  under the ICF Lease,  ICF shall be permitted to impose these same
requirements as a condition to consenting to an assignment or further subletting
under this Sublease.

                  9.5 No assignment  of this  Sublease or further  subletting of
the Sublease  Premises shall relieve Forte of its liability under this Sublease,
which shall remain the primary obligation of Forte.

10.      ALTERATIONS

         10.1 Forte shall have the right (subject to Landlord's  consent,  which
is  to  be  obtained   pursuant  to  Landlord's   Consent  and  Agreement),   to
substantially alter the Sublease Premises, as conceptually  described in Exhibit
6 to this  Sublease  (the "Initial  Alterations").  ICF shall make  available to
Forte  all  plans and  drawings  (including  CAD  materials)  pertaining  to the
existing  improvements  in the  Sublease  Premises.  Forte shall have no duty to
remove the Initial  Alterations or restore the Sublease  Premises  except to the
extent such  removal and  restoration  is  required  by  Landlord's  Consent and
Agreement.

         10.2 Forte may at its  option  and  expense  during  Phase One  install
temporary  wall and lockable doors between the Phase One Space to be occupied by
Forte and the  remainder  of the 7th Floor  which will be occupied by ICF during
Phase One. ICF acknowledges and agrees that during Phase One Forte personnel and
invitees  to the Phase One Space will pass  through  ICF's 7th Floor  offices to
gain access to the Phase One Space and the 7th Floor kitchen facilities.

         10.3  Forte's  Initial  Alterations  in the  Phase  One  Space  will be
conducted  while ICF is occupying  the other half of the 7th Floor.  Forte shall
undertake all reasonable efforts to mitigate  disruption to ICF's use while such
work is being performed.

11.      APPLICABLE LEASE PROVISIONS

         11.1 1CF and Forte  acknowledge  that this Sublease,  as it pertains to
the Sublease  Premises,  is subject and  subordinate  to the ICF Lease,  and the
Parties agree with respect to the ICF Lease that:

                  11.1.1 The following Sections of the Restated Lease are hereby
incorporated  as  provisions  of this  Sublease  applicable to the demise of the
Sublease  Premises,  with the same  force  and  effect  as if such  incorporated
Sections were set forth word for word herein:  6.01,  6.02,  7.01,  7.02,  7.03,
8.01, 8.02, 8.03, 9.01, 9.02, 10.01,  10.02,  10.03, 11.01, 11.02, 11.03, 12.01,
12.02,  12.03,  13.01,  13.02,  13.03, 14.01, 14.03, 15.01, 15.02, 17.01, 17.02,
19.01, 20.01, 21.01, 22.01, 24.01, 25.01, and 27.01.

         11.1.2 The  incorporated  sections  of  the  ICF  lease  referenced  in
              paragraph 11.1.1 are amended or qualified as follows:

                  (a) Without limiting any of its other  obligations  under this
                      Sublease, ICF specifically agrees to pass through to Forte
                      all  financial  and other  benefits  received by ICF under
                      section 6.02 of the ICF lease.

                  (b) Forte shall obtain the use of eleven (11)  parking  spaces
                      during  Phase  I of  the  sublease  term  and  the  use of
                      thirty-eight  (38) additional  parking spaces during Phase
                      II.

                  (c) Notwithstanding any contrary provision of Subsection 14.01
                      (a)  of  the  Restated  Lease;  Forte's  vacation  of  the
                      Sublease  Premises  shall not be an event of default under
                      subpart  (i) of  Subsection  14.01(a)  so long as Forte is
                      performing all other covenants and obligations  imposed by
                      this Sublease,  including without limitation,  the payment
                      of all Rent; on no more than two (2) occasions  during any
                      twelve  (12) month  period  commencing  on  November 1 and
                      ending on October 31 of each calendar year. Forte shall be
                      entitled to a written notice of delinquency in the payment
                      of Rent and a three (3) business  day grace period  before
                      an event of  default is  declared  under  subpart  (ii) of
                      Subsection  14.01 (a); the reference to "thirty (30) days"
                      in  subpart  (iii) of  Subsection  14.01 (a) is changed to
                      "fifteen (15) business days"; and subparts (ix) and (x) of
                      Subsection  14.01 (a) are not incorporated as part of this
                      Sublease.

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<PAGE>

                  (d) The second sentence of Section 14.03 of the Restated Lease
                      are not incorporated as part of this Sublease.

                  (e)  Subsection  27.01  (g)  of  the  Restated  Lease  is  not
                       incorporated as part of this Sublease.


                  11.1.3  Wherever  the words " Landlord " and " Tenant " appear
in those provisions of the ICF Lease which are incorporated by reference in this
Sublease, they are changed to read 'ICF" and "Forte, respectively.

         11.3     [Reserved]

         11.3 In case of any conflict between the incorporated provisions of the
ICF  Lease  and the  other  terms  and  conditions  of this  Sublease  which are
applicable to the Sublease  Premises governed by the ICF Lease, the latter shall
control. If any incorporated provision of the ICF Lease cross-references another
provision of the ICF Lease which is not expressly incorporated in this Sublease,
such  cross-referenced  ICF Lease provision shall not be a part of this Sublease
except  to  the  extent  the  same  is  integral   to  a  fair  and   reasonable
interpretation of the incorporated ICF Lease provision.

12.      MISCELLANEOUS

         12.1 ICF  represents  and warrants  with respect to the ICF Lease that:
(i) the  attached  Exhibit A is a true,  correct  and  complete  copy of the ICF
Lease; (ii) there are no other or additional documents forming a part of the ICF
Lease or constituting an amendment thereto; (iii) the ICF Lease is in full force
and effect and has not been amended or modified;  (iv) ICF is not now, and as of
the Commencement Date will not be, in default or breach of any of the provisions
of the ICF Lease; and (v) ICF has no knowledge of any claim by Landlord that ICF
is in default or breach of any of the provisions of the ICF Lease.

         12.2 Each of ICF and Forte further  represents  and warrants that there
is no brokerage  commission,  finder's fee ,or other similar compensation due to
any person as a result of the Parties' entry into this Sublease, except for such
fees as may be payable  solely by ICF (and not by  Forte),  to  Colliers  Damner
Pike. Each of ICF and Forte shall defend, indemnify, and hold harmless the other
of and from all loss, cost, liability,  and expense arising due to any actual or
alleged breach of the foregoing  representation and warranty by the indemnifying
Party.

         12.3 Whenever this Sublease calls for a Party to perform. any act, such
Party shall be obligated to do so at its sole cost and expense unless  otherwise
expressly provided herein. Whenever this Sublease calls for either Party to give
its consent or  approval,  such  consent or approval  shall not be  unreasonably
withheld or delayed.

         12.4 So long as this  Sublease  remains  in  effect,  ICF  shall  fully
observe,  perform, and discharge all covenants and obligations imposed on ICF by
the ICF Lease.  So lung as Forte is not in default  under  this  Sublease  after
notice and passage of the  applicable  grace period,  Forte shall be entitled to
quiet and peaceable possession of the Sublease Premises, without interference or
hindrance by persons claiming by, through, or under ICF.

         12.5 All notices  required or permitted to be given  hereunder shall be
in writing and shall be (i) delivered personally; (ii) sent by first class mail,
postage prepared,  and  simultaneously  transmitted by facsimile;  (iii) sent by
registered  or  certified  mail,  return  receipt  requested;  or  (iv)  sent by
overnight courier with receipted  delivery,  in each case to ICF or Forte at its
address  indicated below or at such other place or places as either ICF or Forte
may hereafter designate by written notice to the other.



To ICF:                             ICF Kaiser International, Inc.
                                    9300 Lee Highway
                                    Fairfax, VA 22031-1207
                                    Attn.:  Rex Akins
                                    Facsimile No.:  703/934-9740

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To Forte:                           Forte Software, Inc.
                                    1800 Harrison Street
                                    Oakland, CA  94612
                                    Attn.:  Chief Financial Officer
                                    Facsimile No.:  510/869-3480


With a copy to.                     Forte Software, Inc.
                                    1800 Harrison Street
                                    Oakland, CA  94612
                                    Attn.:  Director of Legal Affairs
                                    Facsimile No.:  510/869-3480


Any notice  delivered or sent shall be deemed to have been delivered  under this
Sublease as follows: (a) on the date such notice is personally delivered; or (b)
on the next business day in the case of delivery pursuant to clause (ii) or (iv)
above; and (c) on the date shown on the  return-receipt or, if no date is shown,
three days after the mailing of notice pursuant to clause (iii) above.

13. CONTINGENCY

This Sublease is contingent  upon Landlord  executing and delivering the Consent
to Sublease and Agreement, which ICF and Forte hereby agree to execute.

IN WITNESS WHEREOF,  ICF and Forte have duly executed this Sublease on the dates
set forth below.



ICF                                       Forte

ICF Kaiser Engineers, Inc.,               Forte Software, Inc.,
an Ohio corporation                       a Delaware Corporation

BY:  Rex Akins                            BY:  Robert Gorlin


Its:  Vice President                      Its:  Director of Legal Affairs



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