<PAGE>

                       AMENDED AND RESTATED CREDIT AGREEMENT

         This Amended and Restated Credit Agreement (the "Agreement") is made
as of the 28th day of January, 1998 among the lenders identified on Schedule
I hereto (the "Lenders") and Moldflow Corporation, a Delaware corporation
(the "Company"). This Agreement amends and restates the Credit Agreement
entered into as of the 4th day of December, 1997 among the Lenders and the
Company.

         WHEREAS, the Company desires that the Lenders extend to the Company
a line of credit (the "Line of Credit") on the terms and in an amount set
forth herein;

         WHEREAS, the Lenders are willing to extend the Line of Credit to the
Company on the terms set forth herein;

         NOW THEREFORE, for good and valuable consideration, the receipt and
sufficiency is hereby acknowledged, the parties hereto agree as follows:


                                    ARTICLE 1
              ESTABLISHMENT AND BORROWINGS UNDER THE LINE OF CREDIT

         1.1 AGREEMENT TO LEND. Subject to the terms and conditions set forth
herein, each Lender agrees to make loans to the Company on the terms set
forth in the Convertible Term Note in the form attached hereto as Exhibit A
(the "Note") in two advances during the period (the "Loan Period") from the
date hereof to the second anniversary of the date hereof, in an aggregate
principal amount that will not result in such Lender's loans hereunder
exceeding such Lender's Credit Commitment (as set forth in Schedule I hereto
and as may be increased as set forth herein), PROVIDED that the aggregate of
the loans made by the Lenders hereunder shall not at any time exceed the
total Credit Commitments.

         1.2 REQUESTS FOR ADVANCES. To request a loan hereunder (an
"Advance"), the Company shall provide each of the Lenders with a notice of
such request (an "Advance Request"), which shall be delivered not fewer than
ten (10) days prior to the date on which the funds are to be disbursed. The
Company may request up to two (2) Advances hereunder and may not request in
excess of $500,000 per Advance. Each Advance Request shall specify the
location and number of the Company's account to which funds are to be
disbursed.

         1.3      FUNDING OF ADVANCES.

                  1.3.1 Each Lender shall make an Advance in the Allocable
Loan Amount (as defined below) with respect to each Advance Request by the
tenth day following the delivery of the Advance Request by wire transfer of
immediately available funds to the account of the Company specified in the
Advance Request, against delivery by the Company to each Lender of a Note (in
the attached form) in the amount of such Lender's Advance and dated the date
of such Advance. A Lender's Allocable Loan Amount shall be equal to the total
amount of the Advance requested by the Company in any particular instance
multiplied by a fraction, the

<PAGE>

numerator of which is such Lender's Credit Commitment and the denominator of
which is the total amount of Credit Commitments (a Lender's "Allocable
Percentage").

                  1.3.2 The obligations and rights of each Lender under this
Agreement are several.

                  1.3.3 If any Lender does not make an Advance in accordance
with Section 1.3.1 following receipt of an Advance Request (a "Defaulting
Lender"), then the Company shall so notify the other Lenders. Each other
Lender may elect, by notifying the Company within fifteen (15) days of
receipt of notification from the Company, to have such Lender's Credit
Commitment increased by a pro rata portion of such Defaulting Lender's
Allocable Loan Amount based upon the Loan Commitment of each of the other
Lenders desiring to have their Credit Commitments so increased. Thereafter,
the Defaulting Lender shall not be entitled to make any additional Advances
hereunder. The Company's rights under this Section 1.3.2 with respect to a
Defaulting Lender shall be in addition to all other rights which the Company
may have under law.

         1.4 REPAYMENT OF LOANS. The Company unconditionally promises to pay
to each Lender the then unpaid principal amount, plus any accrued interest,
of such Lender's aggregate loans hereunder on the maturity date of the Note.

         1.5 PREPAYMENT OF LOANS. The Company may, at its option, prepay from
time to time all or any part of the Note in accordance with the conditions of
the Note. In the event that the Company prepays only part of the Note, each
Lender shall be prepaid rateably in the proportion to which its loan bears to
the total amount of loans hereunder.


                                    ARTICLE 2
                                   TERMINATION

         The provisions of Sections 1.1, 1.2 and 1.3 hereof shall terminate
upon the second anniversary of the date hereof.


                                    ARTICLE 3
                                  MISCELLANEOUS

         3.1 RANKING. The Company hereby covenants with each Lender that the
Notes will rank PARI PASSU and rateably without any preference or priority
among themselves and shall not rank junior to any other obligation of the
Company to its shareholders.

         3.2 NOTICES. All notices and other communications provided for
herein shall be in writing and shall be delivered by hand or overnight
courier service, mailed by certified or registered mail or sent by telecopy,
as follows:


                                           2


<PAGE>

                  3.2.1 if to the Company, to Moldflow Corporation, 91
Hartwell Avenue, Lexington, Massachusetts 02173, Attention of President
(Telecopy No. 781-674-0267), with an additional copy to Palmer & Dodge LLP,
One Beacon Street, Boston, Massachusetts 02108, Attention of Marc A.
Rubenstein (Telecopy No. 617-227-4420); and

                  3.2.2 if to the Lenders, at the address set forth on
Schedule I hereto.

         Any party hereto may change its address or telecopy number for
notices and other communications hereunder by notice to the other parties
hereto. All notices and other communications given to any party hereto in
accordance with the provisions of this Agreement shall be deemed to have been
given on the date of receipt.

         3.3 WAIVERS; AMENDMENTS. No failure or delay by a party in
exercising any right or power hereunder shall operate as a waiver thereof,
nor shall any single or partial exercise of any such right or power, or any
abandonment or discontinuance of steps to enforce such a right or power,
preclude any other or further exercise thereof or the exercise of any other
right or power. Neither this Agreement nor any provision hereof may be
waived, amended or modified except pursuant to an agreement or agreements in
writing entered into by the Company and all of the Lenders.

         3.4 SUCCESSORS AND ASSIGNS. The provisions of this Agreement shall
be binding upon and inure to the benefit of the parties hereto and their
respective successors and assigns permitted hereby. Nothing in this
Agreement, expressed or implied, shall be construed to confer upon any person
(other than the parties hereto, their respective successors and assigns
permitted hereby) any legal or equitable right, remedy or claim under or by
reason of this Agreement. Moldflow Corporation may not assign or transfer all
or any part of its rights or obligations under this Agreement other than to a
wholly-owned subsidiary of Moldflow Corporation. In the event that Moldflow
Corporation assigns or transfers all or any part of its rights or obligations
under this Agreement to its wholly-owned subsidiary, Moldflow Corporation
shall guarantee the performance by such wholly-owned subsidiary of its rights
and obligations under this Agreement.

         3.5 COUNTERPARTS; INTEGRATION; REFERENCES TO AGREEMENT;
EFFECTIVENESS. This Agreement may be executed in counterparts (and by
different parties hereto on different counterparts), each of which shall
constitute an original, but all of which when taken together shall constitute
a single contract. This Agreement together with the exhibits and schedules
hereto constitute the entire contract among the parties relating to the
subject matter hereof and supersede any and all previous agreements and
understandings, oral or written, relating to the subject matter hereof.
Delivery of an executed counterpart of a signature page of this Agreement by
telecopy shall be effective as delivery of a manually executed counterpart of
this Agreement.

         3.6 GOVERNING LAW; JURISDICTION; CONSENT TO SERVICE OF PROCESS. This
Agreement shall be construed in accordance with and governed by the law of the
Commonwealth of


                                        3

<PAGE>

Massachusetts. Each party hereto hereby irrevocably and unconditionally
submits, for itself and its property, to the nonexclusive jurisdiction of the
courts of the Commonwealth of Massachusetts and of the United States District
Court for the District of Massachusetts, and any appellate court from any
thereof, in any action or proceeding arising out of or relating to this
Agreement or the Note, or for recognition or enforcement of any judgment, and
each of the parties hereto hereby irrevocably and unconditionally agrees that
all claims in respect of any such action or proceeding may be heard and
determined in such Massachusetts court (or, to the extent permitted by law,
in such Federal court). Each of the parties hereto agrees that a final
judgment in any such action or proceeding shall be conclusive and may be
enforced in other jurisdictions by suit on the judgment or in any other
manner provided by law. Nothing in this Agreement shall affect any right that
any party may otherwise have to bring any action or proceeding relating to
this Agreement against any other party or its properties in the courts of any
jurisdiction.

         3.7 HEADINGS. Article and Section headings used herein are for
convenience of reference only, are not part of this Agreement and shall not
affect the construction of, or be taken into consideration in interpreting,
this Agreement.



                                       4


<PAGE>

         IN WITNESS WHEREOF, the parties hereto have caused this Agreement to
be duly executed by their respective authorized officers as of the day and
year first above written.

COMPANY

SIGNED for and on behalf of MOLDFLOW    )
CORPORATION                             )
in the presence of                      )



/s/ Marc Dulude
---------------------------------
President


Marc Dulude
----------------------------------
Name of president (print)


LENDERS

SIGNED for and on behalf of THOMAS     )
INVESTMENTS AUSTRALIA PTY LTD          )
by a director in the presence of       )



------------------------------------         ---------------------------------
Witness                                      Director


------------------------------------         ---------------------------------
Name of witness (print)                      Name of director (print)

THE COMMON SEAL of HELMET              )
INVESTMENTS AUSTRALIA PTY LTD is       )
affixed in accordance with its         )
articles of association                )
in the presence of                     )



------------------------------------         ---------------------------------
Secretary                                    Director


------------------------------------         ---------------------------------
Name of secretary (print)                    Name of director (print)




                                       5

<PAGE>


         IN WITNESS WHEREOF, the parties hereto have caused this Agreement to
be duly executed by their respective authorized officers as of the day and
year first above written.

COMPANY

SIGNED for and on behalf of MOLDFLOW    )
CORPORATION                             )
in the presence of                      )



---------------------------------
President



----------------------------------
Name of president (print)


LENDERS

SIGNED for and on behalf of THOMAS     )
INVESTMENTS AUSTRALIA PTY LTD          )
by a director in the presence of       )


/s/ Suzanne E. Rogers                        /s/ A. Roland Thomas
------------------------------------         ---------------------------------
Witness                                      Director

Suzanne E. Rogers                            A. Roland Thomas
------------------------------------         ---------------------------------
Name of witness (print)                      Name of director (print)

THE COMMON SEAL of HELMET              )
INVESTMENTS AUSTRALIA PTY LTD is       )
affixed in accordance with its         )
articles of association                )
in the presence of                     )



------------------------------------         ---------------------------------
Secretary                                    Director


------------------------------------         ---------------------------------
Name of secretary (print)                    Name of director (print)




                                       5


<PAGE>


         IN WITNESS WHEREOF, the parties hereto have caused this Agreement to
be duly executed by their respective authorized officers as of the day and
year first above written.

COMPANY

SIGNED for and on behalf of MOLDFLOW    )
CORPORATION                             )
in the presence of                      )



---------------------------------
President



----------------------------------
Name of president (print)


LENDERS

SIGNED for and on behalf of THOMAS     )
INVESTMENTS AUSTRALIA PTY LTD          )
by a director in the presence of       )



------------------------------------         ---------------------------------
Witness                                      Director


------------------------------------         ---------------------------------
Name of witness (print)                      Name of director (print)

THE COMMON SEAL of HELMET              )
INVESTMENTS AUSTRALIA PTY LTD is       )
affixed in accordance with its         )               [SEAL]
articles of association                )
in the presence of                     )


/s/ Pauline Healy                            /s/ Peter Kennedy
------------------------------------         ---------------------------------
Secretary                                    Director

Pauline Healy                                Peter Kennedy
------------------------------------         ---------------------------------
Name of secretary (print)                    Name of director (print)




                                       5

<PAGE>

SIGNED for and on behalf of FLOATFLOW     )                      [SEAL]
PTY LTD by a director in the presence of  )


/s/ Pamela A. Hambling                        /s/ Paul Bordonaro
-----------------------------------           --------------------------------
Witness                                       Director


Pamela A. Hambling                            Paul Bordonaro
-----------------------------------           --------------------------------
Name of witness (print)                       Name of director (print)


THE COMMON SEAL of JTC                    )
INVESTMENT MANAGEMENT PTY is              )
affixed in accordance with its            )
articles of association in the            )
presence of                               )



-----------------------------------           --------------------------------
Secretary                                     Director



-----------------------------------           --------------------------------
Name of secretary (print)                     Name of director (print)

THE COMMON SEAL of WESTPAC                )
CUSTODIAN NOMINEES LIMITED (as            )
nominee for NJI No. 1(A) Investment Fund) )
is affixed in accordance with its         )
articles of association in the            )
presence of                               )



-----------------------------------           --------------------------------
Secretary                                     Director


-----------------------------------           --------------------------------
Name of secretary (print)                     Name of director (print)



                                       6


<PAGE>
SIGNED for and on behalf of FLOATFLOW     )
PTY LTD by a director in the presence of  )



-----------------------------------           --------------------------------
Witness                                       Director



-----------------------------------           --------------------------------
Name of witness (print)                       Name of director (print)


THE COMMON SEAL of JTC                    )
INVESTMENT MANAGEMENT PTY is              )
affixed in accordance with its            )                  [SEAL]
articles of association in the            )
presence of                               )


                                              /s/ Julian Beale
                                              --------------------------------
                                              Director


                                              Julian Beale
                                              --------------------------------
                                              Name of director (print)

THE COMMON SEAL of WESTPAC                )
CUSTODIAN NOMINEES LIMITED (as            )
nominee for NJI No. 1(A) Investment Fund) )
is affixed in accordance with its         )
articles of association in the            )
presence of                               )



                                              --------------------------------
                                              Director



                                              --------------------------------
                                              Name of director (print)

                                       6



<PAGE>
SIGNED for and on behalf of FLOATFLOW     )
PTY LTD by a director in the presence of  )



-----------------------------------           --------------------------------
Witness                                       Director



-----------------------------------           --------------------------------
Name of witness (print)                       Name of director (print)


THE COMMON SEAL of JTC                    )
INVESTMENT MANAGEMENT PTY is              )
affixed in accordance with its            )
articles of association in the            )
presence of                               )



                                              --------------------------------
                                              Director



                                              --------------------------------
                                              Name of director (print)

THE COMMON SEAL of WESTPAC               )
CUSTODIAN NOMINEES LIMITED (as           )
nominee for NJI No. 1(A) Investment Fund))            [SEAL]
is affixed in accordance with its        )
articles of association in the           )
presence of                              )


                                              /s/ illegible
                                              --------------------------------
                                              Director


                                              /s/ illegible
                                              --------------------------------
                                              Name of director (print)






                                       6


<PAGE>

THE COMMON SEAL of WESTPAC               )
CUSTODIAN NOMINEES LIMITED (AS           )             [SEAL]
NOMINEE FOR NJI NO. 1 (B)                )
INVESTMENT FUND)                         )
is affixed in accordance with            )
its articles of association in           )
the presence of                          )



                                              /s/ illegible
                                              --------------------------------
                                              Director


                                              /s/ illegible
                                              --------------------------------
                                              Name of director (print)


SIGNED for and on behalf of AMPERSAND     )
SPECIALTY MATERIALS AND                   )
CHEMICALS II, LIMITED PARTNERSHIP         )
by its general partner ASMC II Management )
Company LP by its general partner         )
ASMC-II MCLP LLP                          )



                                              --------------------------------
                                              Director and General Partner



                                              --------------------------------
                                              Name of director (print)


SIGNED for and on behalf of AMPERSAND     )
SPECIALTY MATERIALS AND                   )
CHEMICALS III, LIMITED PARTNERSHIP        )
by its general partner ASMC III Management)
Company LP by its general partner         )
ASMC-II MCLP LLP                          )



                                              --------------------------------
                                              Director and General Partner



                                              --------------------------------
                                              Name of director (print)



                                       7

<PAGE>

THE COMMON SEAL of WESTPAC               )
CUSTODIAN NOMINEES LIMITED (AS           )
NOMINEE FOR NJI NO. 1 (B)                )
INVESTMENT FUND)                         )
is affixed in accordance with            )
its articles of association in           )
the presence of                          )



-----------------------------------           --------------------------------
Secretary                                     Director


-----------------------------------           --------------------------------
Name of secretary (print)                     Name of director (print)



SIGNED for and on behalf of AMPERSAND     )
SPECIALTY MATERIALS AND                   )
CHEMICALS II, LIMITED PARTNERSHIP         )
by its general partner ASMC II Management )
Company LP by its general partner         )
ASMC-II MCLP LLP                          )


                                              /s/ Charles D. Yie
                                              --------------------------------
                                              Director and General Partner


                                              Charles D. Yie
                                              --------------------------------
                                              Name of director (print)


SIGNED for and on behalf of AMPERSAND     )
SPECIALTY MATERIALS AND                   )
CHEMICALS III, LIMITED PARTNERSHIP        )
by its general partner ASMC III Management)
Company LP by its general partner         )
ASMC-III MCLP LLP                         )


                                              /s/ Charles D. Yie
                                              --------------------------------
                                              Director and General Partner


                                              Charles D. Yie
                                              --------------------------------
                                              Name of director (print)




                                       7






<PAGE>
SIGNED for and on behalf of AMPERSAND     )
SPECIALTY MATERIALS AND                   )
CHEMICALS III COMPANION FUND              )
LIMITED PARTNERSHIP by its general        )
partner ASMC III Management               )
Company LP by its general partner         )
ASMC-III MCLP LLP                         )


                                              /s/ Charles D. Yie
                                              --------------------------------
                                              Director and General Partner


                                              Charles D. Yie
                                              --------------------------------
                                              Name of director (print)



                                       8


<PAGE>

                                    SCHEDULE I


                              MOLDFLOW CORPORATION
                   TABLE OF SHAREHOLDER LOAN PARTICIPATION
                                JANUARY 9, 1998


<TABLE>
<CAPTION>
                                                                 TOTAL          % OF
                                  COMMON       PREFERRED     COMMON SHARE      CURRENT      ALLOCABLE       CREDIT       ADVANCE
                                  SHARES         SHARES       EQUIVALENTS      SHARES       PERCENTAGE    COMMITMENT      AMOUNT
                                                                                                              USD          USD
                                                                                                          -----------------------
                                                                                                          $1,000,000   $  500,000
                                                                                                          -----------------------
<S>                               <C>          <C>           <C>              <C>           <C>           <C>           <C>
PRINCIPAL AMOUNT:

COMMON SHAREHOLDERS:

Thomas Investments Australia
Pty. Ltd.                        344,065              -        344,065           4.62%          4.63%     $   46,289   $   23,145

Helmet Investments Australia
Pty. Ltd.                        344,065              -        344,065           4.62%          4.63%     $   46,289   $   23,145

Floatflow Pty. Ltd.              344,065              -        344,065           4.62%          4.63%     $   46,289   $   23,145

JTC Investment Management
Pty. Ltd.                      3,808,421              -      3,808,421          51.18%         51.24%     $  512,369   $  256,184

Mazza & Riley Inc.                 8,000              -          8,000           0.11%             -               -

PREFERENCE SHAREHOLDERS:

SERIES B CONVERTIBLE
PREFERRED STOCK

Westpac Custodian Nominees
Limited as nominee for NJI
No. 1 (A) Investment Fund         25,000        333,333        358,333           4.82%          4.82%      $  48,209    $   24,104

Westpac Custodian Nominees
Limited as nominee for NJI
No. 1 (B) Investment Fund         25,000        333,333        358,333           4.82%          4.82%      $  48,209    $   24,104
                               ---------     ----------     ----------                                     ---------
TOTAL NJI                         50,000        666,666        716,666                                     $  96,417    $   48,209

SERIES A CONVERTIBLE
PREFERRED STOCK

Ampersand Specialty
Materials and Chemicals II        10,003        928,123        938,126          12.61%         12.62%      $ 126,211    $   63,106

Ampersand Specialty
Materials and Chemicals III        9,837        912,724        922,561          12.40%         12.41%      $ 124,117    $   62,059

Ampersand Specialty
Materials and Chemicals III
Companion Fund                       160         14,841         15,001           0.20%          0.20%      $   2,018    $    1,009
                               ---------     ----------     ----------                                     ---------    ----------
Total Ampersand                   20,000      1,855,688      1,875,688                                     $ 252,347    $  126,174



   TOTAL SHARES ISSUED         4,918,616      2,522,354      7,440,970            100%           100%
   TOTAL LOAN COMMITMENT                                                                                    $1,000,000   $  500,000


</TABLE>