THE DESCARTES SYSTEMS GROUP INC.
                       STOCK OPTION PLAN OPTION AGREEMENT


To:       MARK WEISBERGER

Date:     May 27, 2005

Re:       The Descartes Systems Group Inc. Stock Option Plan

Attached hereto is a copy of The Descartes Systems Group Inc. Stock Option Plan
(the "Plan") that has been approved by the Board of Directors of The Descartes
Systems Group Inc. (the "Company").

This is to advise you that you are entitled to participate in the Plan and have
been granted a conditional option to purchase 100,000 common shares (the
"Shares") in the capital of the Company.

          1. The option is conditional on the Company achieving [text redacted].
          If the condition is not satisfied, the option will immediately expire.

          2. The exercise price of the option is Cdn. $2.64 per share.

          3. Your option may be exercised in whole or in part, subject to the
          vesting schedule described in Section 3, at any time or from time to
          time, up to and including, but not after, MAY 27, 2012 on which date
          your option, unless terminated earlier on the basis set forth in the
          following sentence or the Plan, shall expire. Subject to the
          foregoing, in the event of the termination of your employment with the
          Company or its Affiliates (as defined in the Plan) other than for
          cause or as a result of resignation, that portion of the option that
          has not vested on the date you receive such notice of termination (the
          "Notice Date") shall expire and terminate on the Notice Date, and that
          portion of the option that has vested on the Notice Date shall expire
          and terminate on the date six months after the Notice Date.

          4. Subject to Sections 3 and 7, your option shall vest in accordance
          with the following vesting schedule:

                                   ---------------------- --------------------
                                   VESTING DATE           NO. OF OPTIONS
                                                          FROM GRANT VESTING
                                                          ON THIS VESTING DATE
                                   ---------------------- --------------------
                                   June 1, 2006           6,250
                                   ---------------------- --------------------
                                   September 1, 2006      6,250
                                   ---------------------- --------------------
                                   December 1, 2006       6,250
                                   ---------------------- --------------------
                                   March 1, 2007          6,250
                                   ---------------------- --------------------
                                   June 1, 2007           6,250
                                   ---------------------- --------------------
                                   September 1, 2007      6,250
                                   ---------------------- --------------------
                                   December 1, 2007       6,250
                                   ---------------------- --------------------
                                   March 1, 2008          6,250
                                   ---------------------- --------------------
                                   June 1, 2008           6,250
                                   ---------------------- --------------------
                                   September 1, 2008      6,250
                                   ---------------------- --------------------
                                   December 1, 2008       6,250
                                   ---------------------- --------------------
                                   March 1, 2009          6,250
                                   ---------------------- --------------------
                                   June 1, 2009           6,250
                                   ---------------------- --------------------
                                   September 1, 2009      6,250
                                   ---------------------- --------------------
                                   December 1, 2009       6,250
                                   ---------------------- --------------------
                                   March 1, 2010          6,250
                                   ---------------------- --------------------

          5. The terms and conditions of the Plan are hereby deemed to be
          incorporated into and to form part hereof. If there is a conflict
          between any provision of this Agreement and any provision of the Plan,
          the relevant provision of this Agreement shall prevail.

          6. No share certificates representing the Shares shall be delivered
          until payment of the exercise price for the Shares has been made in
          full.

          7. Notwithstanding any other provision of the Plan or this Agreement,
          if a Change of Control occurs, then all options granted pursuant
          hereto that remain unvested as of the date of any such termination
          shall immediately vest on such date.

<PAGE>

          A "Change in Control" shall be deemed to have occurred if (i) any
          person (as defined in the Securities Act (Ontario)) becomes, after the
          date hereof, the owner or "beneficial owner" (as defined in the
          Securities Act (Ontario)), directly or indirectly, of securities of
          the Company representing 50% or more of the combined voting power of
          the Company's then outstanding securities; (ii) during any two year
          period, individuals who at the beginning of such period constitute the
          Board, including for this purpose any additional director whose
          election was approved by a vote of a majority of the directors then in
          office or who were appointed by the directors then in office, cease
          for any reason to constitute a majority thereof; (iii) the Company
          consummates a merger, amalgamation, arrangement or consolidation of
          the Company or other similar transaction with or into another
          corporation (a "Reorganization"), the result of which is that the
          shareholders of the Company at the time of the execution of the
          agreement relating to the Reorganization own less than 50% of the
          total equity of the corporation surviving or resulting from the
          Reorganization or of a corporation owning, directly or indirectly,
          100% of the total equity of such surviving or resulting corporation;
          or (iv) the sale in one or a series of transactions of all or
          substantially all of the assets of the Company.

If you desire to accept this option, please so indicate in the space below.
Please note that acceptance does not constitute an exercise of the option.
Options must be exercised in accordance with the terms and conditions of the
Plan by completing and submitting a subscription substantially in the form of
Schedule A annexed to the Plan, accompanied by payment in full of the exercise
price of the option.


                                           THE DESCARTES SYSTEMS GROUP INC.


                                           By: /s/ J. Scott Pagan
                                               ---------------------------
                                               Name:  J. Scott Pagan
                                               Title:  Corporate Secretary


I hereby accept the above option and agree to
the terms and the conditions set forth above
including the terms and conditions of the Plan.


/s/ Mark Weisberger
-------------------------
MARK WEISBERGER