Exhibit 10.40

FOURTH AMENDMENT TO LEASE

This  Fourth  Amendment  to Lease  made as of this 20th day of May 1999,  by and
between  Connecticut  General Life  Insurance  Company on behalf of its Separate
Account R ("Landlord") and Object Design, Inc. ("Tenant").

WHEREAS,  25 Mall Road Trust  ("Original  Landlord")  and Tenant  entered into a
lease dated September 15, 1993 (the "Original  Lease") for space in the building
known as 25 Burlington Mall Road, Burlington, Massachusetts (the "Building");

WHEREAS,  Original  Landlord and Tenant entered into a First  Amendment to Lease
dated June 28,1994 and a Second Amendment to Lease dated March 1,1996,  amending
the Original Lease (as so amended, the "Amended Lease");

WHEREAS, Landlord succeeded to Original Landlords interest under the Lease;

WHEREAS,  Landlord  and Tenant  entered  into a Third  Amendment  to Lease dated
December 1,1997, amending the Amended Lease (as so amended, the "Lease");

WHEREAS,  Tenant  exercised  its option to expand the  Premises set forth in the
Third Amendment to Lease,  thereby  expanding the Premises into additional space
containing  approximately  5,818 square feet of rentable floor area on the first
(1st) floor of the Building;

WHEREAS,  Landlord and Tenant wish to further  expand the Premises and otherwise
amend the Lease as set forth herein.

NOW, THEREFORE, for good and valuable consideration, the receipt and sufficiency
of which are hereby acknowledge  Landlord and Tenant agree to amend the Lease as
follows, effective April 15, 1999:

1.   All  capitalized  terms used herein and not defined  herein  shall have the
     meanings ascribed to them in the Lease.

2 .  Section  1.1 of the Lease is hereby  amended  by  deleting  the data  which
corresponds  to the subject set forth below and  replacing  it with the data set
forth below which follows each such subject:

` RENTABLE  ELOOR AREA OF TENANT' S SPACE:  44,770  square feet  (r.s.f.) on the
fifth (5th) floor of the Building and 14,568  square feet  (r.s.f.) on the first
(1st) floor of the Building for a total of 59,338  square feet  (r.s.f.),  which
amount includes 5,123 square feet (r.s.f.) in the Third  Expansion  Premises (as
defined in the Fourth Amendment to Lease) (the "Rentable Floor Area of the Third
Expansion Premises)"


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"ANNUAL BASE RENT:

(a)  With respect to the Original Premises (as defined in the  ThirdAmendment to
     Lease):
(i)  $13.75 (p.r.s.f.) until November 30, 2001;
(ii) $17.50 (p.r.s.f.) from and after December 1, 2001;

(b)  $19.50 (p.r.s.f.) with respect to the Expansion Premises (as defined in the
     Third Amendment to Lease);

(c)  $17.00  (p.r.s.f.)  with respect to the Additional  Expansion  Premises (as
     defined in the Third Amendment to Lease); and

(d)  Effective on the earlier of occupancy of the Third  Expansion  Premises for
     business  purposes or July 1,1999 (the "Rent  Commencement  Date"),  $25.50
     (p.r.s.f.) with respect to the Third Expansion Premises."

"ANNUAL  ESTIMATED  ELECTRICAL  COST TO TENANTS SPACE (INCLUDED IN ANNUAL RENT):
$59,338: $1.00 (P.R.S.F.)"

"ANNUAL RENT:

(a) With respect to the Original Premises:
         (i) until November 30,2001, $750,244.00; .
         (ii) from and after December 1, 2001, $878,126.50;

(b) $407,407.50 with respect to the Expansion Premises;

(c) $151,268.00 with respect to the Additional Expansion Premises; and

(d) Effective on the Rent  Commencement  Date,  $135,759.50  with respect to the
    Third Expansion Premises."

"ANNUAL RENT:

(a) With respect to the Original Premises:

         (i) until November 30, 2001, $13.75 Annual Base Rent (p.r.s.f.)
         + $7.25 Annual Estimated Operating Costs (p.r.s.f.) +$l.OO
         Annual Estimated Electrical Cost to Tenant' s Space (p.r.s.f.)
         = $22.00 Total Rate (p.r.s.f.) X 34,102 rentable square feet =
         $750,244.00; and



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         (ii)  from  and  after  December  1,  2001,  $17.50  Annual  Base  Rent
         (p.r.s.f.) + $7.25 Annual Estimated  Operating Costs (p.r.s.f.) + $1.00
         Annual Estimated Electrical Cost to Tenant' s Space (p.r.s.f.) = $25.75
         Total Rate (p.r.s.f.) X 34,102 rentable square feet = $878,126.50;

  (b)    With  respect  to the  Expansion  Premises,  $19.50  Annual  Base  Rent
         (p.r.s.f.) + $8.00 Annual Estimated  Operating Costs (p.r.s.f.)  +$1.00
         Annual Estimated Electrical Cost to Tenant' s Space (p.r.s.f.) = $28.50
         Total Rate (p.r.s.f.) X 14,295 rentable square feet = $407,407.50;

     (c) With respect to the Additional  Expansion Premises,  $17.00 Annual Base
Rent  (p.r.s.f.) + $8.00 Annual  Estimated  Operating  Costs  (p.r.s.f.) + $1.00
Annual  Estimated  Electrical Cost to Tenant' s Space  (p.r.s.f.) = $26.00 Total
Rate (p.r.s.f.) X 5318 rentable square feet = $151,208.00; and

(d)      Effective on the Rent Commencement Date, with respect to the
         Third Expansion Premises, $25.50 Annual Base Rent (p.r.s.f.) +
         $1.00 Annual Estimated Electrical Cost to Tenant' s Space (p.r.s.f.)
         = $26.50 Total Rate (p.r.s.f.) ~1' 5,123 rentable square feet =
         $135,759.50"

3.       Section 1.2 of the Lease is hereby  amended by  inserting  "Exhibit A-3
         -Plan  Showing the  Additional  Expansion  Premises" and "Exhibit A-4 -
         Plan showing the Third Expansion Premises" after "Exhibit A-2 (revised)
         - Plan Showing the Expansion  Premises"  and attaching  Exhibit A-3 and
         Exhibit A-4 attached hereto to The Lease after Exhibit A-2.

4.       Tenant  acknowledges  that Tenant has had an opportunity to inspect the
         Third  Expansion  Premises shown on Exhibit A-4 attached  hereto (the `
         Third  Expansion  Premises").  The Third Expansion  Premises,  shall be
         delivered to Tenant

As Is, Where Is with all faults and without representation, warranty or guaranty
of any kind by  Landlord  to  Tenant,  except  that  all  Building  systems  and
structures shall be in good working order and conditon

Employing  a  contractor   approved  by  Landlord,   such  approval  not  to  be
unreasonably  withheld or delayed,  Tenant  shall  perform the work  ("Tenant' s
Work") identified in plans and  specifications  for the Third Expansion Premises
(consisting of (i) partition layout plans, (ii) specifications for special HVAC,
mechanical  and  electrical  requirements,  and (iii) a  schedule  of  finishes)
("Plans")  to be  prepared  by or on  behalf  of Tenant  and to be  approved  by
Landlord,  such approval not to be unreasonably  withheld or delayed, each party
agreeing to act  reasonably and in good faith to agree upon the Plans as soon as
reasonably  practicable.  Subject to sound engineering practices and Landlord' s
approval of the Plans,  Tenant  shall be  permitted as part of Tenant' s Work to
replace the four (4) panels of glass facing the lobby with  thermal  clear glass
in accordance  with Exhibit B attached  hereto.  Tenant shall use reasonable and
diligent  efforts to maintain the Building  standard blinds on such windows in a
closed condition.  Except as provided below, Tenant shall perform Tenant' s Work
at Tenant' s sole cost and expense.


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Landlord shall pay an amount to Tenant not to exceed $51,230 to reimburse Tenant
for  out-of-pocket  costs incurred by Tenant in performing  Tenant' s Work. Such
amount  shall be due and payable by Landlord to Tenant no later than thirty (30)
days after the later of (a) notice from Tenant to Landlord  after  completion of
Tenant' s Work  enclosing a copy of a  Certificate  of  Occupancy  for the Third
Expansion Premises and documentation  reasonably  acceptable to Landlord showing
the costs incurred by Tenant in performing Tenant' s Work for which Tenant seeks
reimbursement,  or (b) the Rent Commencement Date,  provided in either case that
Tenant is not default of any of its obligations under the Lease.

5.       Notwithstanding  the  provisions  of  Section  4.2 of the  Lease,  with
         respect  to  the  Third  Expansion  Premises  only,   "Operating  Costs
         Escalation"  as  defined in said  Section  4.2 shall be  determined  by
         substituting  the  actual  Operating  Costs  incurred  by  Landlord  in
         calendar year 1999 (the "Third Expansion Premises Base") for the Annual
         Estimated Operating Costs. In connection therewith, with respect to the
         Third  Expansion   Premises  only,   references  to  "Annual  Estimated
         Operating  Costs"  shall be  deemed  to refer to the  "Third  Expansion
         Premises  Base" with respect to the Third  Expansion  Premises" and the
         "Rentable  Floor Area of  Tenant' s Space"  shall be deemed to refer to
         the "Rentable Floor Area of the Third Expansion Premises".

6.       Tenant and Landlord  represent  and warrant that each has dealt with no
         broker in connection with this transaction  other than Meredith & Grew,
         Inc. and  Spaulding  and Slye and Tenant and Landlord  agree to defend,
         indemnify  and hold the other  harmless  from and  against  any and all
         costs,  expense  or  liability  for any  compensation,  commissions  or
         charges  claimed  by a broker  agent  with which such party has had any
         dealings  other than Meredith & Grew,  Inc. and Spaulding and Slye (for
         which  Landlord  shall be  responsible)  with  respect  to this  Fourth
         Amendment to Lease.

7.       It is  understood  that  Landlord is subject to the  provisions  of the
         Employee  Retirement  Income  Security  Act of 1974,  as amended and in
         effect from time to time ("ERISA") and as a result may be prohibited by
         law from  engaging  in  certain  transactions.  Tenant  represents  and
         warrants to the best of its  knowledge  after due inquiry  that neither
         Tenant nor its  "affiliates"  (as  defined in Part V (c) of  Prohibited
         Transaction  Exemption 84-14,  issued March 12,1984) has, or within the
         immediately  preceding  one year has exercised the authority to appoint
         or terminate  CIGNA  Investments,  Inc. or its  affiliates  as an asset
         manager with respect to the assets of any plan  identified on Exhibit C
         attached hereto.

         a.  Except as amended hereby,  the Lease shall remain unmodified and in
             full force and effect and is hereby ratified and confirmed.


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EXECUTED as a sealed instrument on the date and year first written above.

LANDLORD:
CONNECTICUT GENERAL LIFE
INSURANCE COMPANY, on behalf of its Separate Account R


By: /s/ CIGNA Investments, Inc.
   ----------------------------
Tenant
OBJECT DESIGN, INC
By:      /s/Lacey Brandt
  ----------------------------
Title:   CFO



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