<PAGE>   1
                                                                   EXHIBIT 10.23


                            TENTH AMENDMENT TO LEASE

         THIS TENTH AMENDMENT TO LEASE (this "Amendment"), made and entered into
as of the __28th__ day of ____February_, 2000, by and between NATIONAL OFFICE
PARTNERS LIMITED PARTNERSHIP, a Delaware limited partnership, as landlord
("Landlord"), and FIRSTWAVE TECHNOLOGIES, INC., a Georgia corporation, as tenant
("Tenant")

                                WITNESSETH THAT:

         WHEREAS, Atlanta Overlook Associates #3 ("Original Landlord") and Brock
Control Systems, Inc. ("Original Tenant") entered into that certain Office
Building Lease Agreement (the "Lease"), dated January 30, 1988, for certain
premises (the "Premises") in the building located at 2859 Paces Ferry Road,
Atlanta, Georgia (the "Building");

         WHEREAS, Original Landlord and Original Tenant entered into that
certain First Amendment of Lease dated as of December 27, 1988 (the "First
Amendment");

         WHEREAS, State of California Public Employees Retirement System
("Calpers"), successor-in-interest to Original Landlord, and Original Tenant
entered into that certain Second Amendment of Lease dated as of October 2, 1989
(the "Second Amendment");

         WHEREAS, CALPERS and Original Tenant entered into that certain Third
Amendment of Lease dated as of March 10, 1993 (the "Third Amendment");

         WHEREAS, CALPERS and Original Tenant entered into that certain Fourth
Amendment of Lease dated as of June 24, 1993 (the "Fourth Amendment");

         WHEREAS, CALPERS and Original Tenant entered into that certain Fifth
Amendment of Lease dated as of March 22, 1994 (the "Fifth Amendment");

         WHEREAS, CALPERS and Original Tenant entered into that certain Sixth
Amendment of Lease dated as of September 22, 1994 (the "Sixth Amendment");

         WHEREAS, Original Tenant changed its name to Brock International, Inc.
and Brock International, Inc. ("Brock International") assumed the obligations of
Original Tenant under the Lease, as amended;


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<PAGE>   2

         WHEREAS, CALPERS and Brock International entered into that certain
Seventh Amendment of Lease dated as of January 20, 1998 (the "Seventh
Amendment");

         WHEREAS, Brock International changed its name to "Firstwave
Technologies, Inc." and Tenant assumed the obligations of Brock International
under the Lease, as amended;

         WHEREAS, CALPERS and Tenant entered into that certain Eighth Amendment
of Lease dated as of May 8, 1998 (the "Eighth Amendment");

         WHEREAS, Landlord, as successor-in-interest to CALPERS, and Tenant
entered into that certain Ninth Amendment of Lease dated as of February 3, 2000
(the "Ninth Amendment");

         WHEREAS, the Lease, as modified by the First Amendment, Second
Amendment, Third Amendment, Fourth Amendment, Fifth Amendment, Sixth Amendment,
Seventh Amendment, Eighth Amendment, and Ninth Amendment are sometimes
collectively referred to herein as the "Lease"; and

         WHEREAS, Landlord and Tenant desire extend the term of the Lease, amend
certain other terms and conditions of the Lease, and evidence their agreements
and other matters by means of this Amendment.

         NOW THEREFORE, in consideration of the mutual covenants contained
herein, and other good and valuable consideration, the receipt, adequacy and
sufficiency of which are hereby acknowledged, the Lease is hereby amended and
the parties hereto do hereby agree as follows:

1.       Renewal Term. The term of the Lease is hereby extended for a period of
         five (5) years commencing on November 1, 2000 (the "Effective Date")
         and expiring on October 31, 2005 (the "Renewal Term").

2.       Base Rent. Effective on the Effective Date and continuing during the
         Renewal Term, Base Rent for the Premises shall be as follows:

<TABLE>
<CAPTION>
                Year of            Base Rent per      Annual        Monthly
                 Term              Square Foot      Base Rent      Base Rent
                -------            -------------    ---------      ----------
          <S>                      <C>             <C>            <C>
          11/01/00 - 10/31/01         $23.00       $579,968.00    $48,330.67
</TABLE>

         Commencing on November 1, 2001, and on each anniversary of the
         Effective Date thereafter during the Renewal Term, Base Rent shall
         increase as follows:

                  [(Current Base Rent on a per rentable square foot basis) -
                  (the Initial Operating Costs, calculated with respect to
                  calendar year 2001, on a per rentable square foot basis)] x
                  1.025 + Initial Operating Costs on a per rentable square foot
                  basis

         By way of example only, if the Initial Operating Costs are determined
         to be $8.00 per rentable square foot, then Base Rent commencing on
         November 1, 2001 shall be ($23.00 - $8.00) x 1.025 + $8.00 = $23.38 per
         rentable square foot.

         If the Initial Operating Costs are not known as of November 1, 2001,
         then the Base Rent adjustment shall be calculated as soon as
         practicable and shall be retroactive back to November 1, 2001.



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<PAGE>   3

         On or before January 15 of each calendar year after the calendar year
         in which this Lease is executed (or as soon thereafter as practical),
         Landlord shall provide Tenant with the projected Operating Costs for
         such current calendar year, and Tenant shall thereafter pay the Initial
         Operating Costs for operating the Property and Building in excess of
         the Initial Operating Costs. Such projected Operating Costs in excess
         of the Initial Operating Costs shall be payable in advance on a monthly
         basis by paying one-twelfth (1/12th) of such amount during each month
         of such respective calendar year. If Landlord has not furnished Tenant
         with such comparison by January 15, Tenant shall continue to pay on the
         basis of the prior year's estimate until the month after such
         comparison is given. Landlord shall, within one hundred twenty (120)
         days (or as soon thereafter as practical) after each calendar year
         during the Term provide Tenant an unaudited statement of such year's
         actual Operating Costs. If actual Operating Costs are greater than
         projected Operating Costs, Tenant shall pay Landlord, within thirty
         (30) days of such statement's receipt, Tenant's Share of the difference
         thereof. If such year's projected Operating Costs are greater than the
         actual Operating Costs, Landlord shall credit Tenant, within thirty
         (30) days of such statement issuance, Tenant's Share of the difference
         between projected Operating Costs and actual Operating Costs.

         If this Lease commences at any time other than the first (1st) day of a
         calendar year or terminated at any time other than the last day of a
         calendar year the amount of Operating Costs due from Tenant shall be
         proportionately adjusted based on that portion of the year that this
         Lease was in effect.

3.       Additional Rent. During the Renewal Term, Tenant shall pay, in
         accordance with the terms of Paragraph 5 and Exhibit "B" of the Seventh
         Amendment, Tenant's Share of increases in Operating Costs, except the
         Initial Operating Costs shall mean Operating Costs for the Building for
         calendar year 2001.

4.       Notices. Section 1.5 of the Lease regarding the address of Landlord
         shall be amended to provide that the address of Landlord is, and all
         notices to Landlord shall be sent to:

                           National Office Partners Limited Partnership
                           c/o Hines
                           2839 Paces Ferry Road
                           Suite 120
                           Atlanta, Georgia  30339

5.       Termination Option. Notwithstanding anything to the contrary contained
         in the Lease, in the event that Landlord is unable to reasonably
         accommodate Tenant's expansion needs, or if the Termination Standard
         (as that term is defined below) is met and provided Tenant is not in
         default hereunder, Tenant shall have the option to terminate the Lease,
         effective on April 30, 2003 (the "Termination Date") by providing
         Landlord with written notice of such Termination Option election (the
         "Termination Notice"). Such Termination Notice shall be effective only
         if it is given to Landlord by July 31, 2002 (the "Termination Notice
         Deadline"); accordingly, if Tenant has not given its Termination Notice
         to Landlord prior to the Termination Notice Deadline, this Termination
         Option shall expire and be of no further force or effect, and Tenant
         shall have no right or option to terminate the Lease pursuant to



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<PAGE>   4

         this paragraph at any time after the Termination Notice Deadline. The
         "Termination Standard" shall mean that Tenant satisfies two (2) out of
         the following three (3) requirements as of the date of Tenant's
         Termination Notice: (i) Tenant's shareholder's equity (as determined in
         accordance with generally accepted accounting principles ("GAAP")
         consistently applied) is $5,000,000 or less, (ii) Tenant's quick ratio
         (i.e. Tenant's current assets divided by Tenant's current liabilities)
         is less than 1.5, as determined by GAAP, and (iii) Tenant's cash, cash
         equivalents and investment securities are less than $2,000,000. As a
         condition precedent to any termination of the Lease pursuant to the
         provisions of this paragraph, Tenant must have delivered to Landlord,
         together with its Termination Notice, written certification executed by
         Tenant that it satisfies the Termination Standard and supporting
         documentation evidencing Tenant's compliance, as well as an amount as a
         termination fee equal to the unamortized portion (amortized at eleven
         percent (11%) per annum) of any tenant improvement allowance paid by
         Landlord to Tenant under this Amendment. It is hereby acknowledged that
         any such amount required to be paid by Tenant in connection with such
         early termination is not a penalty but a reasonable pre-estimate of the
         damages which would be incurred by Landlord as a result of such early
         termination of the Lease (which damages are impossible to calculate
         more precisely) and, in that regard, constitutes liquidated damages
         with respect to such loss. Tenant shall continue to be liable for its
         obligations under the Lease up to and through the Termination Date
         including, without limitation, additional rental that accrues pursuant
         to the terms of the Lease, with all of such obligations surviving the
         early termination of the Lease. The rights granted to Tenant under this
         paragraph are personal to Tenant, and in the event of any assignment of
         the Lease or sublease by Tenant, this Termination Option shall
         thenceforth be void and of no further force or effect.

6.       Reduction Option. Provided that Tenant is not in default hereunder,
         Tenant shall have a one-time option (the "Reduction Option") to reduce
         the size of the Premises by excluding therefrom a portion equal to
         approximately 12,237 rentable square feet as shown on Exhibit "A"
         attached hereto (the "Excluded Space"). Such Reduction Option shall be
         subject to the following terms and conditions:

                  a. The Reduction Option shall be effective as of April 30,
                  2003 (the "Reduction Date"), and Tenant shall exercise the
                  Reduction Option by providing Landlord with written notice
                  (the "Reduction Notice") thereof on or before July 31, 2002
                  (the "Reduction Notice Deadline"), including specificity as to
                  square footage and location of the Excluded Space. Such
                  Reduction Notice shall be effective only if it is given to
                  Landlord by the Reduction Notice Deadline; accordingly, if
                  Tenant has not given its Reduction Notice to Landlord prior to
                  the Reduction Notice Deadline, this Reduction Option shall
                  expire and be of no further force or effect, and Tenant shall
                  have no right or option to reduce the size of the Premises
                  pursuant to this paragraph at any time after the Reduction
                  Notice Deadline. If Tenant fails to timely exercise the
                  Reduction Option, it shall lapse unexercised and Tenant shall
                  have no further right to reduce the size of the Premises
                  pursuant hereto.

                  b. Within thirty (30) days after Tenant's exercise of the
                  Reduction Option hereunder, Landlord and Tenant agree to enter
                  into an amendment to the Lease to



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<PAGE>   5
                  document such exercise, which amendment, in addition to the
                  matters outlined above, shall adjust the area of the Premises
                  and all other provisions of the Lease which are affected by a
                  reduction in the size of the Premises.

                  c. Should Tenant fail to enter into an amendment, as set forth
                  above, Landlord may at its option treat such failure as a
                  failure to properly exercise Tenant's Reduction Option and the
                  Reduction Option shall be void and of no further force and
                  effect.

                  d. As a condition precedent to Tenant's exercise of its
                  Reduction Option, Tenant must have delivered to Landlord,
                  together with the Reduction Notice, an amount equal to the
                  unamortized portion of any tenant improvement allowance
                  (amortized at eleven percent (11%) per annum). It is hereby
                  acknowledged that any such amount required to be paid by
                  Tenant in connection with such reduction of the Premises is
                  not a penalty but a reasonable pre-estimate of the damages
                  which would be incurred by Landlord as a result of such
                  reduction of the Premises (which damages are impossible to
                  calculate more precisely) and, in that regard, constitutes
                  liquidated damages with respect to such loss.

                  e. Tenant shall also be responsible for all costs and expenses
                  incurred by Landlord for any necessary construction,
                  (including, without limitation, constructing a demising wall,
                  electricity and plumbing) as a result of the separation of the
                  Excluded Space from the Premises and Tenant shall be
                  responsible for correcting any code violations within the
                  Premises solely caused by the separation of the Excluded Space
                  from the Premises. To the extent that additional common
                  corridors are required due to the separation of the Excluded
                  Space from the Premises, Landlord and Tenant will share
                  equally in the cost of constructing such common corridors.

                  f. If Tenant elects to exercise the Reduction Option, Tenant
                  agrees that it shall not lease any space in any other building
                  in Atlanta, Georgia without first providing Landlord with the
                  right to lease to Tenant similar space on the terms and
                  conditions of a new lease at another building.

                  g. The rights granted to Tenant under this paragraph are
                  personal to Tenant, and in the event of any assignment of the
                  Lease or sublease by Tenant, this Reduction Option shall
                  thenceforth be void and of no further force or effect. In the
                  event that Tenant exercises this Reduction Option, the Right
                  of First Offer (as defined below) of Tenant as set forth
                  hereinbelow shall be void immediately upon the delivery of the
                  Reduction Notice from Tenant to Landlord.

7.       Right of First Offer.

                  a. So long as no event of default on the part of Tenant then
                  exists, and subject to any current right to an expansion
                  option, renewal option, first right to lease or other such
                  right granted to a tenant of the Building prior to the date
                  this Amendment


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<PAGE>   6

                  is executed, and so long as there is no sublease of any
                  portion of the Premises or any assignment of the Lease,
                  Landlord shall not at any time lease all or any portion of the
                  space located on the eleventh (11th) floor of the Building as
                  it becomes available (the "Offer Space"), as more particularly
                  described on Exhibit A, without first giving notice to tenant
                  of the proposed lease with a bona fide prospect for such space
                  (the "Availability Notice"). Such notice shall contain all of
                  the material, economic terms of the proposed lease. Tenant
                  must elect to lease the Offer Space within ten (10) days of
                  the notice from Landlord, by giving notice to Landlord of
                  Tenant's notice. If Landlord does not receive such notice from
                  Tenant within said ten (10) days, Tenant shall be deemed to
                  have elected not to lease the space in question, Tenant shall
                  have no further rights to said space, and Landlord shall be
                  free to lease the space to another party.

                           (b) Tenant shall have the right to lease the Offer
                  Space offered at the then prevailing market base rental rate
                  and leasehold improvement allowance as determined by landlord
                  in is sole, good faith judgment, and indicated by Landlord in
                  the Availability Notice. If Tenant elects to exercise this
                  right to lease, Tenant shall deliver notice of such exercise
                  to Landlord. Upon such notice by Tenant, Tenant shall be bound
                  to lease said portion of said floor on the same terms and
                  conditions as under the Lease, but at the rental rate and
                  other terms as set forth in the Availability Notice.

8.       Tenant Improvement Allowance. Landlord shall provide to Tenant an
         improvement allowance up to $6.00 per rentable square foot of the
         Premises (the "Allowance") to be used towards refurbishment work in the
         Premises. Landlord agrees that it shall refurbish the Premises at
         Landlord's sole cost and expense (subject to reimbursement from, but
         not to exceed, the Allowance), in a good and workmanlike manner
         substantially in accordance with construction drawings and plans to be
         mutually agreed upon by Landlord and Tenant. Otherwise, Tenant hereby
         accepts the Premises "AS IS" (except as otherwise provided herein).
         Except for the Allowance, Tenant shall be responsible for all costs and
         expenses of refurbishing the Premises (including, without limitation, a
         five percent (5%) construction management fee payable to Landlord
         calculated on all costs and expenses of construction).

9.       Extension Option. So long as the Lease is in full force and effect and
         Tenant is not in default thereunder, Tenant shall have the option (the
         "Extension Option") to extend the term for the entire Premises for an
         additional period of five (5) years (the "Extension Period") subject to
         the following terms and conditions:

                  a. Tenant shall not have the right to assign the Extension
                  Option to any sublessee or assignee of the Premises, nor may
                  such sublessee or assignee exercise or enjoy the benefit of
                  such Extension Option.

                  b. Tenant shall have given Landlord written notice of its
                  exercise of the Extension Option on or before nine (9) months
                  prior to the expiration of the Renewal Term.



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<PAGE>   7

                  c. The Extension Option shall only be applicable to the entire
                  Premises, as it may have expanded or contracted from time to
                  time pursuant to the terms of the Lease.

                  d. The terms and conditions of the Lease, as amended from time
                  to time, shall remain in full force and effect during any
                  Extension Period except that the term "Base Rent" shall be
                  modified to mean the rent charged at the Prevailing Market
                  Rate (as hereinafter defined).

                  e. "Prevailing Market Rate" shall mean the then prevailing
                  market rate for rent for leases in similar quality buildings
                  in the market for space comparable to the Premises taking into
                  account such factors offered to third party tenants for
                  comparable space as the base services year for pass-through
                  expenses, the value of the tenant improvements already in
                  place in the Premises at the commencement of the Extension
                  Period, rent concessions, tenant improvement allowances, lease
                  commissions saved or incurred, and moving allowances.

                  f. Within thirty (30) days after the establishment of the
                  Prevailing Market Rate, Landlord and Tenant agree to enter
                  into an amendment to the Lease to evidence the exercise of the
                  Extension Option. If Landlord and Tenant are unable to agree
                  upon the Prevailing Market Rate within such 30-day period,
                  then Tenant's exercise of this Extension Option shall be void
                  and the Lease shall expire at the end of the Renewal Term.

10.      Parking. Landlord shall provide Tenant with four (4) unreserved parking
         spaces per 1,000 usable square feet of the Premises at no charge during
         the Renewal Term. Landlord shall provide Tenant with eight (8) reserved
         parking spaces in the Overlook III parking facility at no charge during
         the Renewal Term. Tenant shall have the right to park in the Building
         parking facilities in common with other tenants of the Building. Tenant
         agrees not to overburden the parking facilities and agrees to cooperate
         with Landlord and other tenants in use of the parking facilities.
         Landlord reserves the right in its absolute discretion to determine
         whether the parking facilities are becoming overburdened and to
         allocate and assign parking spaces among Tenant and other tenants, and
         to reconfigure the parking area and modify the existing ingress to and
         egress from the parking area as Landlord shall deem appropriate.

11.      Deletions and Modifications. Sections 49, 50, 51, 53 and 57 of the
         Lease; Section 307 of the First Amendment; Sections 6, 8 and 10 of the
         Fourth Amendment; Section 3 of the Fifth Amendment; Sections 4 and 5 of
         the Sixth Amendment; and Sections 5 and 7 of the Seventh Amendment
         shall each be deleted in its entirety. Section 7 of the Fourth
         Amendment shall be modified by deleting the phrase "in excess of
         thirty-five thousand (35,000)" and inserting in lieu thereof the phrase
         "the entire 10th floor consisting of twenty-five thousand two hundred
         sixteen (25,216)".

12.      Brokers. Landlord and Tenant hereby represent and warrant to the other
         that neither it nor



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<PAGE>   8

         its officers or agents nor anyone acting on its behalf has dealt with
         any real estate broker other than Hines Properties, Inc. who
         represented Landlord and CB Richard Ellis who represented Tenant in the
         negotiating or making of this Amendment, and Landlord and Tenant hereby
         agree to indemnify and hold the other party, its agents, employees,
         partners, directors, shareholders and independent contractors harmless
         from all liabilities, costs, demands, judgments, settlements, claims,
         and losses, including reasonable attorneys' fees and costs, incurred by
         such party in conjunction with any such claim or claims of any other
         broker or brokers claiming to have interested the Tenant in the
         Building or Premises or claiming to have caused Tenant to enter into
         this Amendment, except as disclosed hereinabove.

13.      Tenant hereby agrees that there are, as of the date hereof, regardless
         of the giving of notice and the passage of time, or both, no defaults
         or breaches on the part of Landlord or Tenant under the Lease.

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

15.      This Amendment represents the entire agreement between the parties
         hereto. Landlord and Tenant agree that there are no collateral or oral
         agreements or understandings between them with respect to the Premises
         or the Building. This Amendment supersedes all prior negotiations,
         agreements, letters or other statements with respect to this
         modification of the Lease.

         EXCEPT AS expressly amended and modified hereby, the Lease shall
otherwise remain in full force and effect, the parties hereto hereby ratifying
and confirming the same. To the extent of any inconsistency between the Lease
and this Amendment, the terms of this Amendment shall control.


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<PAGE>   9


         IN WITNESS WHEREOF, the undersigned parties have duly executed this
Amendment as of the day and year first above written.

                      LANDLORD:

                      NATIONAL OFFICE PARTNERS LIMITED PARTNERSHIP,
                      a Delaware limited partnership

                           By: Hines National Office Partners Limited
                               Partnership, a Texas limited partnership
                               general partner

                               By: Hines Fund Management, L.L.C., a Delaware
                                   limited liability company, its general
                                    partner

                                   By: Hines Interests Limited Partnership,
                                       a Delaware limited partnership its
                                       sole member

                                       By: Hines Holdings, Inc., a Texas
                                           corporation, its general partner

                                           By:
                                              --------------------------------
                                                   Daniel MacEachron
                                                   Vice President

                                           Date Executed by Landlord:

                                           -----------------------------------

                      TENANT:

                      FIRSTWAVE TECHNOLOGIES, INC.,
                      a Georgia corporation

                      By:
                         -----------------------------------------------------
                      Name:
                           ---------------------------------------------------
                      Its:
                           ---------------------------------------------------

                                            (CORPORATE SEAL)

                      Date Executed by Tenant:
                                              --------------------------------
                      Tenant Tax Identification  Number:
                                                        ----------------------


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                                   EXHIBIT "A"

                                 EXCLUDED SPACE


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                                   EXHIBIT 13





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