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                                                                   EXHIBIT 10.26
FIRST AMENDMENT TO COMMERCIAL LEASE

         This First Amendment to Commercial Lease (this "Amendment") is made and
entered into as of December 13, 1999, by and between ACLP University Park SA II,
L.P., a Texas limited partnership ("Lessor"), and Globalscape, Inc., a Texas
corporation ("Lessee") for the purposes more fully described below.

                               R E C I T A L S:
                               ---------------

         A.  Lessor and Lessee are parties to that certain Commercial Lease (the
"Lease") dated as of April 13, 1999, wherein Lessor leased to Lessee the
Premises, as defined in the Lease;

         B.  Lessee and Lessor desire to amend the Lease as provided herein.

                              A G R E E M E N T:
                              -----------------

         NOW THEREFORE, in consideration of the mutual covenants and agreements
herein contained and for other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, Lessor and Lessee hereby amend the
Lease and Lessor and Lessee agree as follows:

         8.  Termination of Right of First Refusal Lessor and Lessee agree that
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             Section 1.07, Leasing Term Limitation on Adjacent Space and Right
             of First Refusal, of the Lease, is hereby terminated and deleted in
             its entirety and that Lessee has no further rights or claim to any
             space in the Building other than the Leased Premises.

         9.  Leased Premises Lessee will take the Initial Space of 7,350 square
             ---------------
             feet and the Must Take Space of 7,350 square feet upon the
             Commencement Date of the Lease. The Leased Premises will comprise
             14,700 total rentable square feet upon the Commencement Date.

         10. Base Rent Section 1.04, Base Rent, Security Deposit, of the Lease
             ---------
             is hereby deleted and replaced in its entirety with the following:

             "1.04 Base Rent, Security Deposit. Base Rent is $15,888.25 net per
             month based upon an assumed 14,700 rentable square footage in the
             Leased Premises and shall be adjusted by $12.97 per rentable square
             foot per year based on the recalculation under Section 1.02 above.
             Security Deposit is $7,974.13."

         11. Improvement Allowance Tenant Improvement Allowance is hereby
             ---------------------
             increased from $22.00 per rentable square foot to $28.00 per
             rentable square foot.

         12. Amortization of Excess Improvement Allowance.
             --------------------------------------------

             (A)   Lessor has increased Lessee's Improvement Allowance and, as a
                   result, hereby deletes in its entirety the third to last
                   sentence in Section 6.01(A) which reads, "Lessee shall be
                   responsible for payment in advance of all work and
                   construction resulting from changes in the Lessee
                   Improvements Final Plans and Specifications requested by
                   Lessee if the additional cost attributable to the changes
                   exceed the Improvement Allowance by more than $3.00 as
                   described in subparagraph (c) below." and replaces it with
                   the following:

                         "Lessee shall be solely responsible for payment in
                         advance of all work and construction resulting from
                         changes in the Lessee Improvements which exceed the
                         Improvement Allowance."
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              (B)  The last two sentences of Section 6.01(C) are hereby
                   deleted in their entirety.

         13.  Miscellaneous
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              a.   Capitalized Terms. Terms not otherwise defined herein shall
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                   have the meanings ascribed thereto in the Lease.

              b.   Effect of Amendment. Except to the extent the Lease is
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                   modified by this Amendment, the remaining terms and
                   provisions of the Lease shall remain unmodified and in full
                   force and effect. In the event of a conflict between the
                   terms of the Lease and the terms of this Amendment, the terms
                   of this Amendment shall prevail.

              c.   Entire Agreement. This Amendment, together with the Lease,
                   ----------------
                   embodies this entire understanding between Lessor and Lessee
                   with respect to its subject matter and can be changed only by
                   an instrument in writing signed by Lessor and Lessee.

              d.   Counterparts. This Amendment may be executed in counterparts,
                   ------------
                   each of which shall be deemed an original, but all of which,
                   together, shall constitute one and the same Amendment.

         IN WITNESS WHEREOF, the parties have executed this Amendment as of the
date and year first set forth above.

LESSOR:                                      LESSEE:

ACLP UNIVERSITY PARK SA II, L.P.,            GLOBALSCAPE, INC.,
a Texas limited partnership                  a Texas corporation

By:  ACLP University Park SA II, L.P.,
     a Texas corporation,
     its general partner                     By: ___________________________
                                                 Name ______________________
                                                 Title: ____________________
     By: ________________________
         Sue Shelton
         Executive Vice President