Document:

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                                                                   Exhibit 10.15

                               AGREEMENT OF LEASE

     THIS AGREEMENT OF LEASE (the "LEASE") made this 27th day of October, 1998,
by and between ANNANDALE FINANCIAL CENTER JOINT VENTURE, a Maryland General
Partnership, (hereinafter referred to as "LANDLORD"), and ONESOFT CORPORATION, a
DELAWARE Corporation, (hereinafter referred to as "TENANT").

     WITNESSETH, that for and in consideration of the rent hereinafter reserved
and of the mutual covenants and agreements hereinafter set forth, Landlord and
Tenant do hereby mutually agree as follows:

PREMISES            1. Landlord does hereby lease to Tenant, and Tenant does
                    hereby lease from Landlord, for the term and upon the
                    covenants and conditions hereinafter set forth, the Premises
                    which shall be deemed to be approximately ONE THOUSAND FOUR
                    HUNDRED SEVENTY-SIX (1,476) RENTABLE SQUARE FEET known as
                    Suite 120 located on the first floor of the Building known
                    as "ANNANDALE FINANCIAL CENTER", located at 7010 Little
                    River Turnpike, Annandale, Virginia 22003 (hereinafter
                    referred to as the "Premises").

TERM                2.(a) The term of this Lease shall commence on the later of
                    (i) the "Substantial Completion" of Landlord s construction
                    of the Premises or (ii) December 1, 1998 (the "LEASE
                    COMMENCEMENT DATE"), and expiring FIVE (5) YEARS after the
                    Lease Commencement Date (the "EXPIRATION DATE"). The period
                    commencing with the Lease Commencement Date (on the first
                    day of the next calendar month in the event the Lease
                    Commencement Date does not occur on the first day of a
                    month) and ending on the last day of the twelfth calendar
                    month thereafter shall constitute the first "Lease Year" as
                    such term is used herein. Each successive full twelve (12)
                    month period during the Lease Term shall constitute a "Lease
                    Year" and any portion of the Lease Term remaining after the
                    last twelve month period during said Lease term shall
                    constitute the last "Lease Year" for the purpose of this
                    lease.

                    (b) The term "Substantial Completion" shall mean that date
                    upon which construction of the improvements to the Premises
                    (as outlined in Paragraph 28. herein) have been
                    substantially completed and approved by local officials
                    having jurisdiction, subject only to normal punch list items
                    that will not materially or adversely interfere with
                    Tenant's business operations.

                    Notwithstanding anything herein to the contrary, Tenant
                    shall have the opportunity to enter the Premises during the
                    fifteen (15) day period prior to the Lease Commencement Date
                    for the purpose of installing computer, data, telephone and
                    television cable lines, special equipment, furniture,
                    fixtures, telephones and other personal property, providing
                    such early
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                    entrance does not unreasonably interfere with Landlord's
                    construction in Premises. Any occupancy prior to the Lease
                    Commencement Date shall be pursuant to all the terms and
                    conditions of this Lease, except that rent shall not
                    commence until the Lease Commencement Date. Within fifteen
                    (15) days after the Lease Commencement Date, Landlord and
                    Tenant shall execute a Certificate of Commencement.

RENT                3.(a) During and for the Term hereof, commencing on the
                    Lease Commencement Date, Tenant covenants and agrees to pay
                    Landlord for the Premises, without notice or demand and
                    without deduction, set off or abatement, a fixed minimum
                    guaranteed base rent (hereinafter sometimes referred to as
                    the "BASE RENT") payable in monthly installments, in
                    advance, (hereinafter sometimes referred to as "MONTHLY BASE
                    RENT" ) as follows:

                    Lease Year   Annual Base     Monthly     Rent Per
                                    Rent        Base Rent   Square Foot
                    -----------------------------------------------------

                        1        $29,520.00     $2,460.00      $20.00

                        2         30,996.00      2,583.00       21.00

                        3         32.545.80      2,712.15       22.05

                        4         34.173.09      2.847.76       23.15

                        5         35.881.74      2,990.15       24.31
                    -----------------------------------------------------

                    Tenant shall pay all rent to Landlord at the office of
                    Landlord, or to such other party or at such other address as
                    Landlord may designate from time to time by written notice
                    to Tenant. Rent shall be paid on or before the first day of
                    each and every calendar month, without prior notice, during
                    the Term hereof, provided, however that the Monthly Base
                    Rent for the First month of the Term shall be payable upon
                    execution of this Lease.

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                    (b) Tenant covenants and agrees to pay to Landlord a Late
                    Fee equal to FIVE percent (5%) of the Monthly Base Rent if
                    any such payment is not received by Landlord within TEN (10)
                    days of their due date. In addition, all delinquent payments
                    due Landlord, including, but not limited to, rent and
                    additional rent, shall bear interest at the rate of TWO
                    percent (2%) per annum above the "Prime Rate" as published
                    by Wall Street Journal, New York, New York, as of the date
                    such payment became due, for the period beginning on the
                    date such payment became due to the date of payment thereof
                    by Tenant, provided, however, that nothing herein contained
                    shall be construed or implemented in such a manner as to
                    allow Landlord to charge or receive interest in excess of
                    the maximum rate then allowed by law. All such late fees and
                    interest charges shall be deemed additional rent due
                    hereunder and shall be payable with the next installment of
                    Monthly Base Rent.

OPERATING EXPENSES  4. Intentionally DELETED
AND REAL ESTATE
TAXES

DELAYED             5.(a) If Landlord shall be unable to give possession of the
POSSESSION          Premises on the Lease Commencement Date specified in Section
                    2 of this Lease for any reason, such failure to do so shall
                    not affect or impair the validity of this Lease or the
                    obligations of Tenant hereunder, except as expressly
                    provided herein, and Landlord shall not be subject to any
                    liability for damages for such failure to give possession on
                    said date. In such event, Landlord shall notify Tenant in
                    writing setting forth a new Lease Commencement Date as
                    specified in Section 2 of this Lease. Unless such delay is
                    due to the fault of Tenant, the Base Rent reserved and
                    covenanted to be paid herein shall not commence until the
                    date that possession of the Premises is given to Tenant, or
                    the Premises are available for occupancy by Tenant and
                    Tenant has been so notified by Landlord, whichever shall
                    first occur.

                    (b) If for any reason the Landlord shall be unable to give
                    possession of the Premises to Tenant more than TWO (2)
                    months after the Lease Commencement Date specified in
                    Section 2, then Tenant shall have the option to cancel this
                    Lease after such date by giving THIRTY (30) days prior
                    written notice of such termination to the other party. If
                    Landlord shall tender possession of the Premises to Tenant
                    after Tenant has given notice such notice but prior to the
                    expiration of such THIRTY (30) day period, any notice given
                    by Tenant shall thereupon be nullified. Upon any such
                    cancellation becoming effective, Landlord and Tenant shall
                    be entirely relieved of the obligations hereunder, and any
                    security deposit given by Tenant to Landlord shall be
                    returned to Tenant.

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USE OF PREMISES      6. Tenant shall use and occupy the Premises solely as a
                    general office space, provided that such use(s) is in
                    accordance with applicable zoning and other local
                    governmental regulations. Without the prior written consent
                    of Landlord, the Premises shall not be used for any other
                    purposes or uses whatsoever. Tenant shall not use or occupy
                    the Premises for any unlawful purpose, and shall comply with
                    all present and future laws, ordinances, regulations, and
                    orders of the United States of America, Commonwealth of
                    Virginia, County of Fairfax, and any other public or
                    quasi-public authority having jurisdiction over the
                    Premises.

ASSIGNMENT          7.(a) Tenant shall not assign, transfer, mortgage, or
AND                 otherwise encumber this Lease, or sublet, rent, or permit
SUBLETTING          occupancy or use of the Premises, or any part thereof,
                    without obtaining the prior written consent of Landlord,
                    which shall not be unreasonably withheld, nor shall any
                    subletting, assignment or transfer of this Lease or the
                    right of occupancy hereunder be effected by operation of law
                    or in any manner other than with the prior written consent
                    of Landlord. Any assignment or subletting or transfer with
                    or without Landlord's consent shall not be construed as a
                    waiver or release of Tenant from liability hereinbefore the
                    payments of rent or the performances and observance of any
                    of the terms and conditions of this Lease. The collection or
                    acceptance of rent from any assignee, subtenant, or occupant
                    shall not constitute a waiver or release of Tenant from any
                    covenant or obligation contained in this Lease, nor shall
                    any assignment or subletting be construed to relieve Tenant
                    from the obligation to obtain the consent in writing of
                    Landlord to any further assignment or subletting.

                    (b) In the event that Tenant desires to assign or sublet all
                    or a portion of the Premises, Tenant shall give to Landlord
                    THIRTY (30) days written notice of Tenant's intention to do
                    same, the name, address and a current financial statement of
                    the proposed subtenant or assignee, and a copy of the
                    proposed assignment or sublease, specifying, among other
                    items, the proposed use, the term and the rent of the
                    proposed sublease or assignment. Within TEN (10) days after
                    receipt of said notice, Landlord shall give written notice
                    to Tenant, stating whether Landlord approves or disapproves
                    the proposed assignment or sublease, Tenant may sublet or
                    assign the Premises only after first obtaining the written
                    consent of Landlord, which consent shall not be unreasonably
                    withheld as set forth hereinabove.

                    (c) In the event that Tenant defaults hereunder, Tenant
                    hereby assigns to Landlord the rent due from any subtenant
                    or assignee of Tenant and hereby authorizes each such
                    subtenant or assignee to pay said rent directly to Landlord.

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MAINTENANCE         8. Tenant shall keep the Premises, fixtures and equipment
BY TENANT           therein in clean, safe sanitary and good order, will suffer
                    no waste or injury thereto, condition and will, at the
                    expiration or other termination of this Lease, surrender the
                    same, broom clean, in the same order and condition in which
                    they are on the Lease Commencement Date, ordinary wear and
                    tear excepted. Maintenance and repair of all equipment
                    and/or fixtures within or for the exclusive benefit of the
                    Premises, including, but not limited to, kitchen fixtures,
                    special air conditioning equipment, bathroom fixtures,
                    computers, or any other type of equipment or improvements,
                    together with related plumbing, electrical, or other utility
                    services, whether installed by Tenant or by Landlord on
                    behalf of Tenant, shall be the sole responsibility of
                    Tenant, and Landlord shall have no obligation in connection
                    therewith.

HOURS OF OPERATION  9. The regularly scheduled hours of operation for Building
                    shall be between EIGHT O'CLOCK (8:00 a.m.) to SIX O'CLOCK
                    (6:00 p.m.), Monday through Friday, and eight O'CLOCK (8:00
                    a.m.) to ONE O'CLOCK (1:00 p.m.) Saturday. Holidays on which
                    said water for the HVAC system shall not be provided except
                    at additional cost are: New Year's Day, Washington's
                    Birthday, Memorial Day, Independence Day, Labor Day,
                    Thanksgiving Day, Christmas Day, and Easter Sunday. Such
                    holidays shall be observed on the dates on which the same
                    are observed by the federal government. If Tenant desires
                    air conditioning/heat and or other utilities or services
                    beyond the hours of operation as hereinabove set forth, and
                    of mutually satisfactory written agreements are made with
                    Landlord, or its agent, not less than TWENTY-FOUR (24) hours
                    in advance of the requirement. Landlord shall use its best
                    efforts to furnish such air conditioning/heating and/or
                    other utilities or services to tenant, and Tenant agrees to
                    pay Landlord the additional costs of such services in an
                    amount equal to ONE HUNDRED TEN percent (110%) of the total
                    direct costs of providing such additional services on an
                    overtime basis. Provided, however, that Landlord and its
                    agent shall not be liable for failure to furnish or for
                    suspension or delay in furnishing any or all of such
                    services caused by breakdown, maintenance or repair work,
                    strike, riot, civil commotion, or any other cause or reason
                    whatsoever beyond the control of Landlord.

                    Building Services. Throughout the Term, Landlord agrees that
                    -----------------
                    the Building will be maintained in a manner befitting a
                    first-class rental office building in the Annandale,
                    Virginia area and that it will furnish, or cause to be
                    furnished, the following services to the Premises and
                    Building, excluding emergency conditions beyond Landlord
                    control:

                    (a) Normal and usual cleaning and janitorial services after
                    5:00 p.m. on business days.

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                    (b) Automatically operated elevator services TWENTY-FOUR
                    (24) hours a day, SEVEN (7) days a week, 365 days a year;

                    (c) All electric bulbs and fluorescent tubes in light
                    fixtures in the public areas of the Building and all
                    standard light bulbs and fluorescent tubes in the Premises;

                    (d) An intercom type security access system located at the
                    front door of the Building. Tenant shall be given access
                    cards into the Building 24 hours a day, 7 days a week, 365
                    days a year;

                    (e) Normal and usual maintenance of the life-safety systems,
                    the elevators, the Garage and all Building improvements and
                    facilities;

                    (f) Heating, ventilating and air-conditioning to the
                    Premises between the hours of 8:00 a.m. and 6:00 p.m. on
                    business days and between the hours of 8:00 a.m. to 1:00
                    p.m. Saturday, excluding holidays;

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TENANT              10. (a) Tenant shall not make or permit anyone to make any
ALTERATIONS         alterations, additions, or improvements, structural or
                    otherwise, or install any fixtures (hereinafter collectively
                    referred to as "Alterations"), in or to the Premises or the
                    Building without the prior written consent of Landlord. All
                    of such Alterations permitted by Landlord must conform to
                    all rules and regulations established from time to time by
                    the Underwriters' Association of the local area and by the
                    Landlord and conform to all requirements of the Federal,
                    State and local governments. Prior to the commencement of
                    work on any Alterations, the Landlord's written approval
                    must be obtained as to (i) the contractor(s) and
                    subcontractor(s) selected to perform such work, and (ii)
                    comprehensive plans and specifications showing all the
                    proposed Alterations, including detailed descriptions of the
                    effect of the proposed Alterations on the mechanical and
                    electrical systems of the Building. Landlord shall have the
                    right to stop such work if the Landlord or its designated
                    agent determines that such work is not being done in a
                    workmanlike manner or in accordance with the plans and
                    specifications provided to Landlord. In such event, Tenant
                    shall promptly correct the problem(s) which give rise to the
                    work stoppage, and if Tenant fails to do so within a time
                    period determined by Landlord to be reasonable, then
                    Landlord may. at its sole option, correct such problem(s),
                    or complete the Alterations, or remove the Alterations and
                    restore the Premises to their original condition, and Tenant
                    shall be liable for the costs of such action as additional
                    rent. Copies of all plats, plans, sketches, permits,
                    samples, etc. which are prepared or obtained in the course
                    of such Alterations shall be provided to the Landlord or its
                    designated agent no later than TEN (10) days after such are
                    prepared or obtained. The Tenant agrees to pay to the
                    Landlord or its designated agent a reasonable inspection fee
                    and to allow inspection from time to time during the period
                    of construction of all Alterations. In addition, Tenant
                    agrees to furnish "as built" plans and specifications for
                    all Alterations within a reasonable period of time after
                    completion of Alterations, and to pay to Landlord, or its
                    designated agent, a reasonable fee for updating the master
                    reproducible Building blueprint to show the Alterations.

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                    (b) Prior to commencing construction on any Alterations
                    approved by Landlord, Tenant agrees to obtain and deliver to
                    Landlord written and unconditional waivers of mechanic's and
                    materialman's liens upon the Property for all work, labor
                    and services to be performed and materials to be furnished,
                    by them in connection with such work, signed by all
                    contractors, subcontractors, materialmen, and laborers to
                    become involved in such work. If notwithstanding the
                    foregoing, any mechanic's or materialmen's lien is filed
                    against the Property for work claimed to have been done for,
                    or materials claimed to have been furnished to, Tenant, such
                    lien shall be discharged by Tenant within ten (10) days
                    thereafter, at Tenant's sole cost and expense, by the
                    payment thereof or by filing any bond required by law. If
                    Tenant shall fail to discharge any such mechanic's or
                    materialman's lien, Landlord may, at its option, discharge
                    the same and treat the cost thereof and any legal expenses
                    incurred in connection therewith, as additional rent payable
                    with the installment of Monthly Base Rent next becoming due;
                    it being hereby expressly covenanted and agreed that such
                    discharge by Landlord shall not be deemed to waive or
                    release the default of Tenant in not discharging the same.
                    It is understood and agreed by Landlord and Tenant that any
                    such Alterations shall be constructed on behalf of Tenant.
                    It is further understood and agreed that, in the event
                    Landlord shall give its written consent to Tenant's making
                    any such Alterations, such written consent shall not be
                    deemed to be an agreement or consent by landlord to subject
                    Landlord's interest in the Property to any mechanic's or
                    materialman's liens which may be filed in respect of any
                    such Alterations made by or on behalf of Tenant.

                    (c) Tenant shall indemnify and hold Landlord harmless from
                    and against any and all expenses, liens, claims, or damages
                    to any person or property which may or might arise directly
                    or indirectly by reason of making of any such Alterations.

                    (d) If any Alterations are made without the prior written
                    consent of Landlord, Landlord retains the right to enter the
                    Premises at any time during the Term of this Lease to
                    correct or remove the same and restore the Premises to their
                    condition prior to the construction of the unauthorized
                    Alterations, and Tenant shall be liable and hereby agrees to
                    reimburse the Landlord for the costs of such removal and
                    restoration together with any and all damages which the
                    Landlord may suffer and sustain as a result thereof.

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                    (e) All Alterations, including wall-to-wall carpet and wall
                    covering, to, in or upon the Premises shall, unless the
                    Landlord elects otherwise, become the property of Landlord
                    and shall remain upon the Premises and be surrendered with
                    Premises at the expiration or termination of this Lease, or
                    any renewal or extension period, without disturbance,
                    molestation or injury. Should the Landlord elect that
                    Alterations made by the Tenant upon the Premises be removed
                    upon the expiration or termination of this Lease, or any
                    renewal period, the Tenant hereby agrees to cause same to be
                    removed at the Tenant's sole cost and expense, and to
                    restore the Premises to the original improved condition, on
                    or before the expiration or termination of this Lease or any
                    renewal period. Should Tenant fail to remove the same or
                    restore the Premises, the Landlord may cause same to be
                    removed and/or the Premises to be restored at the Tenant's
                    expense, and the Tenant hereby agrees to pay to the Landlord
                    the cost of such removal and/or restoration together with
                    any and all damages which the Landlord may suffer and
                    sustain by reason of the failure of the Tenant to remove the
                    same and/or restore the Premises as herein provided.

                    (f) If Tenant is not in default in the performance of any of
                    its obligations under this Lease, Tenant shall have the
                    right to remove, prior to the expiration of the Term of this
                    Lease, all movable equipment, furniture or furnishings which
                    are not affixed to the Premises or the Building and which
                    were installed in the Premises at the expense of Tenant. If
                    such property of Tenant is not removed by Tenant prior to
                    the expiration or termination of this Lease, the same shall
                    become the property of Landlord and shall be surrendered
                    with the Premises as a part thereof, or, at Landlord's
                    option, Landlord may cause the same to be removed and the
                    Premises to be restored to their original improved
                    condition, and Tenant hereby agrees to pay to Landlord the
                    cost of such removal and restoration together with any and
                    all damages which Landlord may suffer and sustain by reason
                    of the failure of Tenant to remove the same and restore the
                    Premises or Building as herein provided.

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ADVERTISING         11. Except as otherwise herein provided, Tenant agrees that
                    no sign, advertisement, display or notice shall be
                    inscribed, painted or affixed on any part of the outside or
                    inside of the Premises or Building, except on the
                    directories and doors of offices, and then only in such
                    size, color and style as the Landlord shall approve.
                    Landlord shall have the right to prohibit any advertisement,
                    or display of items of the Tenant, wherever appearing, which
                    in the Landlords reasonable opinion tends to impair the
                    reputation of the Building or its desirability as a building
                    for offices or for financial, insurance or other
                    institutions and businesses of like nature. Upon written
                    notice from the Landlord, Tenant shall refrain from and
                    discontinue such advertisement. In the event that Tenant
                    violates the terms of this section, Landlord may remove any
                    sign, advertisement, display or notice and may charge the
                    Tenant for any costs incurred by Landlord in connection with
                    such removal.

                    Notwithstanding the foregoing, Tenant shall have the right
                    to affix exterior signage to the Building at Tenant's sole
                    cost and expense. Tenant shall provide Landlord with a scale
                    drawing of the sign and proposed location on the Building,
                    and such sign and location shall be subject to Landlord's
                    approval and any governmental and historic restrictions.

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DELIVERIES          12. No freight, furniture or other bulky matter of any
                    description shall be received into the Building or carried
                    in the elevators, except as approved by the Landlord. All
                    moving of furniture, material and equipment in the Building
                    outside the Premises must be with the prior written consent
                    of the Landlord and in accordance with Landlord's reasonable
                    rules and instructions; however, Landlord shall not be
                    responsible for any damage to, or charges for, moving the
                    same. Tenant agrees to remove promptly from the public
                    area(s) within or adjacent to the Building any of Tenant's
                    personal property there delivered or deposited. Landlord
                    shall have the right to prescribe the weight, method of
                    installation, and position of safes or other heavy fixtures
                    or equipment. All damage done to the Building by delivery,
                    maintaining or removal of any fixture or article of Tenant's
                    furniture or equipment, shall be repaired at the expense of
                    Tenant.

EQUIPMENT           13. Tenant shall not install or operate in the Premises any
                    electrically operated equipment or other machinery, except
                    typewriters, adding machines, copiers, personal computers,
                    and such other office machinery and equipment as is normally
                    used in the operation of Tenant's business, without
                    obtaining the prior written consent of Landlord, which shall
                    not be unreasonably withheld or delayed, but may be
                    conditioned upon the payment by Tenant of additional rent in
                    compensation for any excess consumption of water and/or
                    electricity as may result from the operation of said
                    equipment or machinery. Tenant shall not install any
                    equipment of any kind or nature which shall or may
                    necessitate changes, replacements, or additions to, or cause
                    an abnormal increase in its use of the water, plumbing,
                    heating, air conditioning, or electrical systems, which
                    serve the Premises, without the prior written consent of
                    Landlord. Such consent shall not be withheld unreasonably,
                    but may be conditioned upon the payment of Tenant of the
                    cost of such changes replacements, additions, or increased
                    use. Notwithstanding the foregoing, in the event that office
                    equipment or mechanical equipment used by Tenant in the
                    Premises shall cause noise or vibration that may be
                    transmitted to any part of the Building to such a degree as
                    to be objectionable to Landlord or any other tenant, Tenant
                    shall install, at its own expense, vibration eliminators or
                    silencing devices sufficient to eliminate such noise and/or
                    vibration. Tenant shall not install in the Premises any
                    fixtures, equipment, machinery, furniture or furnishings
                    which place a load upon the floor exceeding the designed
                    floor load capacity.

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INSPECTIONS;        14. Tenant agrees to allow Landlord, its agents or employees
ENTRY               to enter the Premises at all reasonable times to examine,
                    inspect or protect the same; to prevent damage or injury to
                    the same and/or to and other portion of the Building; to
                    make such alterations, additions, improvements and repairs
                    to the Premises or adjacent portions of the Building as
                    Landlord may deem necessary or desirable; or to exhibit the
                    same to prospective tenants during the last SIX (6) months
                    of the Term of this Lease, or any renewal or extension
                    period, or to prospective purchasers of the Building or any
                    portion thereof at any time. None of the same shall be
                    construed as an eviction, actual or constructive. The rent
                    reserved shall not abate while such alterations, additions,
                    improvements or repairs are being made, or because of such
                    inspections or exhibitions, whether by reason of loss or
                    interruption of Tenant's business or otherwise. Landlord
                    agrees to make all reasonable efforts to minimize any
                    disruption of Tenant's business by reason of such
                    activities. Landlord's right of entry for any purpose shall,
                    however, be subject to any State or Federal laws and
                    regulations that may currently enlist or may become
                    applicable because of any secret, confidential, or other
                    restricted activities carried on by Tenant in the Premises.

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INSURANCE           15.(a) Insurance Rating. Tenant will not conduct or permit
                           ----------------
                    to be conducted any activity other than normal office
                    business nor will Tenant place any equipment in or about the
                    Premises or the Property which will, in any way, increase
                    the rate of property and casualty or other insurance on the
                    Property. If any increase in the rate of property and
                    casualty insurance or other insurance is stated by any
                    insurance company or by the applicable Insurance Rating
                    Bureau to be due to any activity or equipment of Tenant in
                    or about the Premises or the Property, such statements shall
                    be conclusive evidence that the increase in such rate is due
                    to such activity or equipment, and, as a result thereof,
                    Tenant shall be liable for such increase and shall reimburse
                    Landlord therefor upon demand. Any such sum due Landlord
                    shall be considered additional rent payable hereunder.

                    (b) Liability Insurance. Tenant shall carry public liability
                        -------------------
                    insurance with a company or companies licensed to do
                    business in the Commonwealth of Virginia and rated not lower
                    than Level A, Class XII, as rated in the most recent edition
                    of "Best's Key Rating Guide" for insurance companies. Said
                    insurance shall cover all liability of Tenant and its
                    authorized representatives arising out of and in connection
                    with Tenant's use or occupancy of the Premises and the
                    Property. Said insurance shall be in minimum amounts set
                    forth in the rules and regulations established by Landlord
                    from time to time such amounts to be reasonable for Tenant's
                    type of business; a copy of the current rules and
                    regulations is attached hereto as Exhibit A. Said insurance
                    shall name Landlord, and the building management agency as
                    additional insured, as their interests may appear, and shall
                    contain an endorsement that said insurance shall remain in
                    full force and effect notwithstanding that the insured has
                    waived his right of action against any party prior to the
                    occurrence of a loss. A current Certificate of Insurance
                    from such insurer shall be delivered to Landlord's agent
                    prior to the Lease Commencement Date and renewals thereof
                    shall be delivered to Landlord's agent at least THIRTY (30)
                    days prior to the expiration of any such policy. Each policy
                    shall contain an endorsement that will prohibit its
                    cancellation prior to the expiration of THIRTY (30) days
                    after written notice to Landlord of such proposed
                    cancellation.

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                    (c) Waiver of Subrogation. Each party hereby waives, and
                        ---------------------
                    shall have included in its liability insurance policies for
                    the Building and/or property insurance covering Tenant's
                    contents, furniture, furnishings, fixtures and other
                    property, appropriate clauses pursuant to which each party's
                    insurance carriers waive, all rights of subrogation against
                    the other party, its principals, agents and employees, with
                    respect to losses payable under such policies, or
                    appropriate clauses setting forth that such policies shall
                    not be invalidated should the insured waive in writing prior
                    to a loss any or all right of recovery against any party for
                    losses covered by such policies. If either party at any time
                    is unable to obtain inclusion of either of the clauses
                    described in the preceding sentence, then such party shall
                    have the other party named in such policies as an additional
                    insured, as their interests may appear. If either party
                    shall be named as an additional insured in accordance with
                    the foregoing provisions, and if the main insured shall not
                    be in default hereunder, and, if progress satisfactory to
                    Landlord is being made with regard to repairs to any damage
                    to the Premises or improvements therein, the additional
                    insured shall promptly endorse to the order of the main
                    insured, without recourse, any check, draft or order for the
                    payment of money representing the proceeds of any such
                    policy, or representing any other payment under such
                    policies, and the additional insured hereby irrevocably
                    waives any and all rights in and to such proceeds and
                    payments. Each party shall advise the other party promptly
                    as to the coverage or language of the clauses included in
                    its insurance policies pursuant to this paragraph and shall
                    notify the other party promptly of any cancellation or
                    change of the terms of any such policies which would affect
                    such clauses. All Certificates of Insurance provided
                    hereunder shall set forth the waiver of subrogation
                    provisions contained in the subject policy.

                    (d) Property and Casualty Insurance. Tenant covenants and
                        -------------------------------
                    agrees to maintain standard property and casualty insurance
                    covering its property located in, on or about the Premises.
                    Said insurance shall be replacement cost, all risk coverage
                    for all leasehold improvements other than the building
                    standard improvements. Tenant shall deliver a Certificate of
                    Insurance from its insurer to Landlord's agent prior to the
                    Lease Commencement Date, and renewals thereof shall be
                    delivered to Landlord's agent at least THIRTY (30) days
                    prior to the expiration of any such policy.

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                                       14
<PAGE>

DAMAGES             16. All breakage, injury or damage to the Premises or to
TO PREMISES         Property, including damage to carpeting, wall finishes, and
                    other items of improvement thereto, in any way caused by
                    Tenant or its agents, employees, contractors, visitors,
                    guests and invitees, shall be repaired at the expense of the
                    Tenant, except those covered by standard fire and extended
                    coverage perils insurance. Landlord shall make, or cause to
                    be made, such necessary repairs, alterations and
                    replacements, structural, nonstructural or otherwise, and
                    any charge, costs or damages so incurred by the Landlord
                    shall be paid by the Tenant. Landlord shall be entitled to
                    regard such charges, costs or damages as additional rent,
                    payable with the installment of Monthly Base Rent next
                    becoming due under this Lease. This provision shall be
                    construed as an additional remedy granted to Landlord and
                    not in limitation of any other rights and remedies which
                    Landlord has or may have.

WAIVER OF           17. (a) Tenant's Property and Personal Injury. All personal
LIABILITY                   -------------------------------------
INDEMNITY           property of Tenant (for the purposes of this Section, the
                    term "Tenant" shall include Tenant, its agents, employees,
                    contractors, visitors, guests and invitees) contained in the
                    Premises shall be and remain there at the sole risk of
                    Tenant. Landlord and/or its agents and employees shall not
                    be liable for any accident or damage to property of Tenant
                    resulting from the use or operation of elevators, heating,
                    cooling, electrical or plumbing apparatus, water, steam, or
                    any other cause; nor shall they be liable for any personal
                    injury to Tenant arising from the use, occupancy and/or
                    condition of the Premises or Property unless such injury
                    shall directly result directly from the gross negligence or
                    willful misconduct of Landlord; nor shall they be liable in
                    any event for any interruption or loss of Tenant's business.
                    Notwithstanding any other language contained herein,
                    Landlord and/or its agents and employees shall not be liable
                    to Tenant for any loss, damage or injury to person or
                    property, even if the same is caused by their negligence or
                    willful misconduct, to the extent that Tenant is compensated
                    therefore by Tenant's insurance.

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                                       15
<PAGE>

                    (b) Tenant's Indemnity. Tenant shall indemnify and hold
                        ------------------
                    Landlord and it's agents and employees harmless from all
                    loss, damage, liability, cost or expense incurred, suffered,
                    or claimed by any person or entity by reason of injury,
                    loss, or damage to any person, property or business
                    resulting from any default hereunder by Tenant, or from
                    Tenant's willful act, negligence or negligent or unlawful
                    use of the Premises or the Property or anything therein,
                    including but not limited to, water, steam, electricity, or
                    other facilities or equipment. Landlord and/or its agents
                    and employees assume no liability or responsibility
                    whatsoever with respect to the conduct and operation of the
                    business to be conducted by Tenant in the Premises, and
                    shall not be liable for any accident or injury to any person
                    or property which are caused by the conduct and operation of
                    Tenant's business. Tenant agrees to indemnify and hold
                    harmless Landlord, its agents and employees, against all
                    such claims.

BANKRUPTCY          18. All of the terms and provisions of this paragraph 18 are
                    made expressly subject to and governed by the provisions of
                    the United States Bankruptcy Code and the orders, rulings
                    and other determination of any bankruptcy court of
                    appropriate jurisdiction relating to the Tenant and/or this
                    Lease. Thus, any provision of this paragraph which is
                    contrary to or in any' way inconsistent with the provisions
                    of the United States Bankruptcy Code or any order, ruling or
                    other determination of any bankruptcy court of appropriate
                    jurisdiction shall, be deemed invalid and of no force and
                    effect.

                    (a) In the event that Tenant shall become a Debtor under
                    Chapter 7 of the Bankruptcy Code, and the Trustee or Tenant
                    shall elect to assume this Lease for the purpose of
                    assigning the same or otherwise, such election and
                    assignment may only be made if all of the terms and
                    conditions of subsection (b) and subsection (d) of this
                    Section 18 are satisfied. If such Trustee shall fail to
                    elect or assume this Lease within sixty (60) days after the
                    filing of the Petition, this Lease shall be deemed to have
                    been rejected. Landlord shall be thereupon immediately
                    entitled to possession of the Premises without further
                    obligation to Tenant or Trustee, and this Lease shall be
                    canceled, but Landlord's right to be compensated for damages
                    in such liquidation proceeding shall survive.

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                                       16
<PAGE>

                    (b) In the event that a Petition for reorganization or
                    adjustment of debts is filed concerning Tenant under
                    Chapters 11 and 13 the Bankruptcy Code, or a proceeding is
                    filed under Chapter 7 of the Bankruptcy Code and is
                    transferred to Chapter 11 or 13, the Trustee or Tenant, as
                    Debtor-In-Possession, must elect to assume this Lease within
                    SEVENTY-FIVE (75) days from the date of the filing of the
                    Petition under Chapters 11 or 13, or the Trustee or
                    Debtor-In-Possession shall be deemed to have rejected this
                    Lease. No election by the Trustee or Debtor-In-Possession to
                    assume this Lease, whether under Chapters 7, 11 or 13, shall
                    be effective unless each of the following conditions, which
                    Landlord and Tenant acknowledge are commercially reasonable
                    in the context of a bankruptcy proceeding of Tenant, have
                    been satisfied, and Landlord has so acknowledged in writing:

                    (1) The Trustee or the Debtor-in-Possession has cured, or
                    has provided Landlord adequate assurance (as defined below)
                    that:

                        (A)  Within TEN (10) days from the date of such
                             assumption the Trustee will cure all monetary
                             defaults under this Lease; and

                        (B)  Within THIRTY (30) days from the date of such
                             assumption the Trustee will cure all non-monetary
                             defaults under this Lease.

                    (2) The Trustee or the Debtor-in-Possession has compensated,
                    or has provided to Landlord adequate assurance (as defined
                    below) that within TEN (10) days from the date of
                    assumption. Landlord will be compensated for any pecuniary
                    loss incurred by Landlord arising from the default of
                    Tenant, the Trustee, or the Debtor-in-Possession as recited
                    in Landlord's written statement of pecuniary loss sent to
                    the Trustee or the Debtor-in-Possession.

                    (3) The Trustee or the Debtor-In-Possession has provided
                    Landlord with adequate assurance of the future performance
                    of each of Tenant's, Trustee's or Debtor-In-Possession's
                    obligations under this Lease; provided, however, that:

                        (A)  The Trustee or Debtor-In-Possession shall also
                             deposit with Landlord as security for the timely
                             payment of rent, an amount equal to THREE (3)
                             months' base Rent and other monetary charges
                             accruing under this Lease; and

                        (B)  If not otherwise required by the terms of this
                             Lease, the Trustee or Debtor-In-Possession shall
                             also pay in advance on the date Monthly Base Rent
                             is payable, ONE-TWELFTH (1/12) of Tenant's annual
                             obligations under this Lease for operating expenses
                             real estate taxes, and similar charges.

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                                       17
<PAGE>

                        (C)  The obligations imposed upon the Trustee or
                             Debtor-In-Possession shall continue with respect to
                             Tenant or any assignee of the Lease after the
                             completion of bankruptcy proceedings.

                    (4) The assumption of the Lease will not:

                    (A) Breach any provision in any other lease, mortgage,
                    financing agreement or other agreement by which Landlord
                    is bound relating to the Building; or

                    (B) Disrupt, in Landlord's judgment, the tenant mix of the
                    Building or any other attempt by Landlord to provide a
                    specific variety of commercial tenants in the Building
                    which, in Landlord's judgment, would be most beneficial to
                    all of the tenants of the Building and would enhance the
                    image, reputation, and profitability of the Building.

                    (C) For purposes of this subsection (b), Landlord and Tenant
                    acknowledge that, in the context of a bankruptcy proceeding
                    of Tenant, at a minimum "adequate assurance" shall mean:

                    (i) The Trustee or the Debtor-In-Possession has and will
                    continue to have sufficient unencumbered assets after the
                    payment of all secured obligations and administrative
                    expenses to assure Landlord that the Trustee or
                    Debtor-In-Possession will have sufficient funds to fulfill
                    the obligations of Tenant under this Lease, and to keep the
                    Premises stocked with inventory and properly staffed with
                    sufficient employees to conduct a fully-operational,
                    actively promoted business on the Premises; and

                    (ii) The Bankruptcy Court shall have entered an Order
                    segregating sufficient cash payable to Landlord and/or the
                    Trustee or Debtor-In-Possession shall have granted valid and
                    perfected first lien and security interest and/or mortgage
                    in property of Tenant, Trustee or Debtor-In-Possession,
                    acceptable as to value and kind to Landlord, to secure to
                    Landlord the obligation of the Trustee or
                    Debtor-In-Possession to cute the monetary and/or
                    non-monetary defaults under this Lease within the time
                    period set forth above.

                    (c) In the extent that this Lease is assumed by a Trustee
                    appointed for Tenant or by Tenant as Debtor-In-Possession
                    under the provisions of subsection (b) hereof and thereafter
                    Tenant is liquidated of debts under Chapters 11 or 13 of the
                    Bankruptcy Code, then, and in either of such events,
                    Landlord may, at its option, terminate this Lease and all
                    rights of Tenant hereunder, by giving Tenant written notice
                    of its election to so terminate, by no later than THIRTY
                    (30) days after the occurrence of either of such events.

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                                       18
<PAGE>

                    (d) If the Trustee or Debtor-In-Possession has assumed the
                    Lease pursuant to the terms and provisions of subsections
                    (a) or (b) herein, for the purpose of assigning (or elects
                    to assign) Tenant's interest under this Lease, or the estate
                    created thereby, to any other person, such interest or
                    estate may be so assigned only if Landlord shall acknowledge
                    in writing that the intended assignee has provided adequate
                    assurance as defined in this subsection (d) of future
                    performance of all of the terms, covenants and conditions of
                    this Lease to be performed by Tenant.

                    For purposes of this subsection (d), Landlord and Tenant
                    acknowledge that, in the context of a bankruptcy proceeding
                    of Tenant, at a minimum "adequate assurance of future
                    performance" shall mean that each of the following
                    conditions have been satisfied, and Landlord has so
                    acknowledged in writing:

                    (1) The assignee has submitted a current financial statement
                    audited by a Certified Public Accountant which shows a net
                    worth and working capital in amounts determined to be
                    sufficient by Landlord to assure the future performance by
                    such assignee of Tenant's obligations under this Lease:

                    (2) The assignee, if requested by Landlord, shall have
                    obtained guarantees in form and substance satisfactory to
                    Landlord from one or more persons who satisfy Landlord's
                    standards of creditworthiness:

                    (3) Landlord has obtained all consents or waivers from any
                    third party required under any lease, mortgage. financing
                    arrangement or other agreement by which Landlord is bound in
                    order to permit Landlord to consent to such assignment.

                    (e) When, pursuant to the Bankruptcy Code, the Trustee or
                    Debtor-In-Possession shall be obligated to pay reasonable
                    use and occupancy charges for the use of the Premises or any
                    portion thereof, such charges shall not be less than the
                    Base Rent as defined in this Lease and other monetary
                    obligations of Tenant for the payment of operating expenses,
                    real estate taxes, and similar charges.

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                                       19
<PAGE>

                    (f) Neither Tenant's interest in the Lease, nor any lesser
                    interest of Tenant herein, nor any estate of Tenant hereby
                    created, shall pass to any trustee, receiver, assignee for
                    the benefit of creditors, or any other person or entity, or
                    otherwise by operation of law under the laws of any state
                    having jurisdiction of the person or property of Tenant
                    (hereinafter referred to as the "state law") unless Landlord
                    shall consent to such transfer in writing. No acceptance by
                    Landlord of rent or any other payments from any such
                    trustee, receiver, assignee, person or other entity shall be
                    deemed to have waived, nor shall it waive the need to obtain
                    Landlord's consent of Landlord's right to terminate this
                    Lease for any transfer of Tenant's interest under this Lease
                    without such consent.

                    (g) In the event the estate of Tenant created hereby shall
                    be taken in execution or by other process of law, or if
                    Tenant or any guarantor of Tenant's obligations hereunder
                    (hereinafter referred to as the "guarantor") shall be
                    adjudicated insolvent pursuant to the provisions of any
                    present or future insolvency law under state law, or if any
                    proceedings are filed by or against the guarantor under the
                    Bankruptcy Code, or any similar provisions of any future
                    federal bankruptcy law, or if a Receiver or Trustee of the
                    property of Tenant or the guarantor shall be appointed under
                    state law by reason of Tenant's or the guarantor's
                    insolvency or inability to pay its debts as they become due
                    or otherwise, or if any assignment shall be made of Tenant's
                    or the guarantor's property for the benefit of creditors
                    under state law, then and in such event Landlord may, at its
                    option, terminate this Lease and all rights of Tenant
                    hereunder by giving Tenant written notice of the election to
                    so terminate within THIRTY (30) days after the occurrence of
                    such event.

                    As used in this Section 18, the term "Tenant" shall include
                    any surety or other guarantor of this Lease.

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                                       20
<PAGE>

CASUALTY            19. In the event of damage by fire or other casualty to the
                    Premises or any part thereof, this Lease shall not be
                    terminated unless otherwise provided hereinafter, but
                    Landlord shall diligently proceed to repair and restore the
                    same. During the period that Tenant is deprived of the use
                    of the damaged portion of the Premises, provided that such
                    damage was not caused by the negligence or willful
                    misconduct of Tenant, its agents, employees, contractors,
                    visitors, guests or invitees, the rent for the remainder of
                    the Premises shall be that portion of the total rent which
                    the area remaining that can be occupied bears to the total
                    area of the Premises, so long as Tenant shall be able to
                    operate its business normally; if Tenant shall be unable to
                    operate its business normally, then rent shall be abated
                    during such period. If during the Term of this Lease the
                    Premises shall be so damaged by fire or other casualty as to
                    be untenantable, then unless said damage be repaired within
                    ONE HUNDRED TWENTY (120) days after said fire or other
                    casualty, either party, upon written notice to the other
                    party given at any time following the expiration of ONE
                    HUNDRED TWENTY (120) days thereafter, may terminate this
                    Lease, in which case the rent and additional rent shall be
                    apportioned and paid to the date of said fire or other
                    casualty. In the event that the Building is so severely
                    damaged or destroyed by fire or other casualty (although the
                    Premises may not be affected) that Landlord shall decide
                    within SIXTY (60) days following such event of casualty not
                    to rebuild or construct the Building, then Landlord shall
                    give written notice to Tenant and this Lease and the tenancy
                    hereunder shall terminate in accordance with such notice.

CONDEMNATION        20. (a) Tenant agrees that if the Premises or a substantial
                    part thereof shall be taken, or sold under the threat of
                    condemnation, for public or quasi-public use or purpose by
                    or to any competent authority, this Lease shall fully
                    terminate as of the date of any such taking. Tenant shall
                    have no claim against Landlord and shall have no claim or
                    right to any portion of the award which may be made to
                    Landlord as a result of any such condemnation: all rights of
                    Tenant to damages therefor, if any, are hereby assigned by
                    Tenant to Landlord. Upon such condemnation or taking, the
                    Term of this Lease shall cease and terminate from the date
                    of such taking or condemnation, and Tenant shall have no
                    claim against Landlord for the value of any unexpired term
                    of this Lease, leasehold improvements, or good will.
                    Notwithstanding the foregoing, Tenant shall be free to
                    pursue a separate claim against the condemning authority for
                    the depreciated value of its leasehold improvements,
                    provided that any award to Tenant shall not result in a
                    diminution of any award to Landlord.

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                                       21
<PAGE>

                    (b) If less than a substantial part of the Premises is taken
                    or condemned, the rent for the remainder of the Premises
                    shall be that portion of the total rent which the area
                    remaining that can be occupied bears to the total area of
                    the Premises, effective on the date when title vests in such
                    governmental authority. The Lease shall otherwise remain in
                    full force and effect. For purposes hereof, a substantial
                    part of the Premises shall be considered to have been taken
                    if Tenant shall be unable to operate its business in its
                    normal and customary manner.

DEFAULT             21. (a) It is agreed that Tenant shall be in default if
                    Tenant shall fail to pay the rent (including any additional
                    rent) at the time the same shall become due and payable as
                    provided hereunder in Section 3(a) of this Lease, and Tenant
                    shall not cure such default within TEN (10) days after the
                    date due and payable for payment of such rent; or if Tenant
                    shall breach, violate, fail, or neglect to keep and perform
                    any of the other terms, covenants, or conditions herein
                    contained, or contained in the Building Instruments, and
                    Tenant shall not cure such breach within THIRTY (30) days
                    after written demand by Landlord therefor, or, if such
                    breach cannot reasonably be cured within such period, Tenant
                    shall fail to diligently attempt to cure such breach, or if
                    the Premises shall become vacant or abandoned (provided that
                    Landlord shall not construe any vacation or abandonment of
                    the Premises before the expiration of the Term hereof as a
                    default so long as Tenant continues to comply with all
                    covenants and conditions of the Lease).

                    (b) In the event of default by Tenant, then and in each such
                    case, Landlord may treat the occurrence of such event as a
                    breach of this Lease, and in addition to any and all other
                    rights or remedies of Landlord in this Lease or at law or in
                    equity provided, it shall be, at the option of Landlord,
                    without further notice or demand of any kind to Tenant or
                    any other person:

                    (i) The right of Landlord, even though it may have relet the
                    Premises as herein below provided, to declare the Lease Term
                    ended and to re-enter the Premises and take possession
                    thereof and remove all persons therefrom, and Tenant shall
                    have no further claim thereon or thereto;

                    (ii) The right of Landlord to bring suit for the collection
                    of rent and other charges, as it accrues pursuant to the
                    terms of this Lease, and damages (including without
                    limitation reasonable attorneys' fees and the cost of
                    renovating the Premises) without entering into possession of
                    said Premises or canceling this Lease;

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                                       22
<PAGE>

                    (iii) The right of Landlord to re-enter or retake possession
                    of the Premises from Tenant by summary proceedings or
                    otherwise and to remove, or cause to be removed, Tenant or
                    any other occupants from the premises in such manner as
                    Landlord shall deem advisable with or without legal process
                    and using self-help if necessary, and it is agreed that the
                    commencement and prosecution of any action by Landlord in an
                    unlawful detainer, ejectment or otherwise or any execution
                    of any judgment or decree obtained in any action to recover
                    possession of the Premises or any other re-entry and removal
                    shall not be construed as an election to terminate this
                    Lease whether or not such entry or re-entry be had or taken
                    under summary proceedings or otherwise, and shall not be
                    deemed to have absolved or discharged Tenant from any of its
                    obligations or liabilities for the remainder of the Term.
                    Tenant shall, notwithstanding any such entry or re-entry,
                    continue to be liable for the payment of rent and the
                    performance of the other covenants, conditions and
                    agreements by Tenant to be performed as set forth in this
                    Lease, and Tenant shall pay to Landlord all monthly
                    deficits, after any such reentry, in monthly installments as
                    the amounts of such deficits from time to time are
                    ascertained. In the event of any such ouster, Landlord shall
                    have the right but not the duty to rent or lease the
                    Premises to some other person, firm or corporation (whether
                    for a term greater or less than or equal to the unexpired
                    portion of the Term or whether the space leased by the new
                    lease includes more or less floor area than the Premises)
                    upon such terms and conditions and for such rental as the
                    Landlord may deem proper and to collect said rental and any
                    other rental that may thereafter become payable. In such
                    event, the rentals received by Landlord from such reletting
                    shall be applied: first, to the payment of any indebtedness
                    other than the rent due hereunder from Tenant to Landlord;
                    second, to the payment of any cost of such reletting
                    (including without limitations the making of any
                    alterations, repairs or decorations in the Premises which
                    Landlord deems advisable); third, to the payment of the cost
                    of any alterations and repairs to the Premises; third, to
                    the payment of rent due and unpaid hereunder, and the
                    residue, if any, shall be held by Landlord and applied in
                    payment of future rent as the same may become due and
                    payable hereunder. Should that portion of such rentals
                    received from such reletting during any month, which is
                    applied to the payment of rent hereunder, be less than the
                    rent payable during that month by Tenant hereunder, then
                    Tenant shall pay such deficiency to Landlord. Such
                    deficiency shall be calculated and paid monthly; Tenant
                    shall have no right to any excess. Tenant shall also pay to
                    Landlord, as soon as ascertained, any costs and expenses,
                    including, but not limited to, brokerage commissions and
                    attorneys' fees, incurred by Landlord in such reletting or
                    in making such alterations and repairs not covered by the
                    rental received from such reletting. Nothing herein
                    contained shall be

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                                       23
<PAGE>

                    construed as obligating the Landlord to relet the whole or
                    any part of the Premises whatsoever. In the event of any
                    entry or taking possession of the Premises as aforesaid,
                    Landlord shall have the right, but not the obligation, to
                    remove therefrom all or any part of the personal property
                    located therein and may place the same in storage at a
                    public warehouse at the expense and risk of the owner or
                    owners thereof. The terms "re-enter" or "re-entry" as used
                    in this Lease are not and shall not be restricted to their
                    technical meaning but are used in their broadest sense.

                    (c) If Landlord elects to terminate this Lease under the
                    provisions set forth above, Landlord may recover from Tenant
                    as damages (all of which shall be immediately due and
                    payable from Tenant to Landlord), in addition to its other
                    remedies:

                    (i) Any' unpaid rent, including interest thereon, which is
                    due and owing at the time of such termination: plus

                    (ii) That rent, including interest thereon, which would have
                    been earned after termination until the time of judgment:
                    plus

                    (iii) A sum representing liquidated damages and not penalty
                    in an amount equal to the excess of the Base Rent for the
                    Premises at the time of termination and the additional rent
                    provided for in Section 4 above for the year in which this
                    Lease shall be terminated multiplied by the number of years
                    and tradition of a year then constituting the remainder of
                    the Term hereof, over the rental value of the Premises at
                    the time of termination for such unexpired Term, discounted
                    at a rate of SEVEN percent (7%) per annum to present value,
                    less commissions, advertising, cost of repairs and other
                    expenses incidental to reletting of such Premises.

                    Nothing herein contained shall limit or prejudice the right
                    of the Landlord to prove and obtain as liquidated damages in
                    any bankruptcy, insolvency, receivership, reorganization or
                    arrangement proceeding an amount equal to the maximum
                    allowed by any statute or rule of law governing such
                    proceedings and in effect at the time when such damages are
                    to be proved, whether or not such amount be greater, equal
                    to or less than the amount of the excess referred to in the
                    preceding sentence. In determining the rental value of the
                    Premises, the commercially reasonable rental realized by any
                    reletting accomplished or accepted by Landlord within a
                    reasonable time after termination of this Lease, shall be
                    deemed, prima facie, to be the rental value.

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                                       24
<PAGE>

                    (iv) Any other amount necessary to compensate Landlord for
                    all the detriment directly caused by Tenant's failure to
                    perform its obligations under this Lease or which in the
                    ordinary course of things would be likely to result
                    therefrom including without limitation to cost of renovating
                    the Premises and reasonable attorneys' fees; plus

                    (v) At Landlord's election, such other amounts, in addition
                    to or in lieu of the foregoing, as may be permitted from
                    time to time by applicable law.

                    (d) In the event of default, all of the Tenant's fixtures,
                    furniture, equipment, improvements, additions, alterations,
                    and other personal property shall remain on the Premises and
                    in that event and continuing during the length of said
                    default, Landlord shall have the right to take exclusive
                    possession of same and to use the same, rent or charge free,
                    until all defaults are cured or, at its option, at any time
                    during the Lease Term, to require Tenant to forthwith remove
                    same. In connection with the foregoing, Landlord shall have
                    a lien upon the property of Tenant in the Premises during
                    the Lease Term for the amount of any unpaid rent or other
                    sum due from Tenant hereunder. Except upon expiration of
                    this Lease where no default exists in the payment of rent or
                    other sums due from Tenant hereunder. Tenant shall not
                    remove any of Tenant's property from the Premises without
                    the prior written consent of Landlord, other than pursuant
                    to sale thereof in the regular course of its business, and
                    Landlord shall have the right and privilege at its sole
                    option and discretion, to take possession of all property of
                    Tenant in the Premises, to store the same in said Premises,
                    or to remove it therefrom and store it in such place as may
                    be selected by Landlord, at Tenant's risk and expense. in
                    accordance with such lien and of any rights of distraint it
                    may possess against Tenants said property.

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                                       25
<PAGE>

                    (e) In the event of a breach or threatened breach by Tenant
                    of any of the covenants or provisions hereof, Landlord shall
                    have the right of injunction and the right to invoke any
                    remedy allowed at law or in equity as if re-entry, summary
                    proceedings and other remedies were not therein provided
                    for; and in such event Landlord shall be entitled to recover
                    from Tenant, payable as additional rent hereunder, any and
                    all reasonable expenses as Landlord may incur in connection
                    with its efforts to secure such injunctive relief or other
                    remedy at law or in equity, such as court costs and
                    attorneys' fees. Landlord and Tenant hereby expressly waive
                    trial by jury in any action, proceeding or counterclaim,
                    brought by either of them against the other, on any matter
                    whatsoever arising out of or in any way connected with this
                    Lease, their relationship as Landlord and Tenant, Tenant's
                    use and occupancy of the Premises and/or any claim of injury
                    or damage. If Landlord shall commence any proceeding for
                    non-payment of rent, or any other payment of any kind to
                    which Landlord may be entitled or which it may claim
                    hereunder, Tenant will not interpose any counterclaim or
                    set-off of whatever nature or description in any such
                    proceeding, the parties hereto specifically agreeing that
                    Tenant's covenants to pay rent or any other payments
                    required of it hereunder are independent of all other
                    covenants and agreements herein contained, provided,
                    however, that this shall not be constructed as a waiver of
                    Tenant's rights to assert such a claim in any separate
                    action brought by Tenant. Tenant further waives any right of
                    defense which may have to claim a merger, and neither the
                    commencement of any action or proceeding settlement thereof
                    nor entering of judgment shall bar Landlord from bringing
                    subsequent actions or proceedings from time to time. Mention
                    in this Lease of any particular remedy shall not preclude
                    Landlord from any other remedy at law or in equity to which
                    it may be entitled. Tenant hereby expressly waives any and
                    all rights of redemption granted by or under any present or
                    future laws in event of Tenant being evicted or dispossessed
                    for any cause, or in the event of Landlord obtaining
                    possession of the Premises by reason of the violation by
                    Tenant of any of the covenants and conditions of this Lease,
                    or otherwise.

                    (f) It is further provided that, if legal proceedings are
                    instituted hereunder, and a compromise or settlement thereof
                    shall be made, it shall not be constituted as a waiver of
                    any breach of any covenant, condition or agreement herein
                    contained.

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                                       26
<PAGE>

                    (g) No payment by Tenant or receipt by Landlord of a lesser
                    amount than the Monthly Base Rent herein stipulated shall be
                    deemed to be other than on account of the earliest
                    stipulated rent then due, nor shall any endorsement or
                    statement on any check or any letter accompanying any check
                    or payment of rent be deemed an accord and satisfaction, and
                    Landlord may' accept such check or payment without prejudice
                    to Landlord's right to recover the balance of such rent or
                    to pursue any other remedy.

                    (h) Should Tenant fail to pay rent (including any additional
                    rent) as and when the same is due, Landlord shall not be
                    required to wait until the expiration of the Term hereof to
                    sue for Landlord's loss or damages, but shall have the right
                    to sue from time to time to recover unpaid rent and other
                    damages as provided in this Lease. Landlord shall have the
                    option to declare the entire balance of the Base Rent
                    (including annual increases as provided herein) immediately
                    due and payable upon failure by Tenant to cure any default
                    within the time prescribed herein. Landlord shall have the
                    further option to defer action until the expiration of the
                    Term, in which event the cause of action shall not be deemed
                    to have accrued until the date of expiration. All rights and
                    remedies of Landlord under this Lease shall be cumulative
                    and shall not be exclusive of any other rights and remedies
                    provided to Landlord under applicable law.

                    (i) If, prior to the commencement of the Term of this Lease,
                    Tenant notifies Landlord of or otherwise unequivocally
                    demonstrates an intention to repudiate this Lease, Landlord
                    may, at its option, consider such anticipatory repudiation a
                    breach of this Lease. In addition to any other remedies
                    available to it hereunder or at law or in equity, Landlord
                    may retain all rent paid upon execution of the Lease and the
                    security deposit, if any, to be applied to damages of
                    Landlord incurred as a result of such repudiation,
                    including, without limitation, attorneys' fees, brokerage
                    fees, costs of reletting and loss of rent. It is agreed
                    between the parties that for the purpose of calculating
                    Landlord's damages, in a building which has other available
                    space at the time of Tenant's breach, Landlord shall have no
                    obligation to rent the Premises prior to other space in the
                    Building.

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                                                                           -----

                                       27
<PAGE>

SUBORDINATION       22. This Lease is subject and subordinate to all ground or
                    underlying leases, if any, and to any deeds of trust which
                    may now or hereafter affect this Lease or the Property, and
                    to all renewals, modifications, consolidations, replacements
                    and extensions thereof. Notwithstanding the foregoing,
                    Tenant shall have the right to keep the Lease in full force
                    and effect so long as Tenant shall fully comply with all the
                    terms of this Lease. This clause shall be self-operative and
                    no further instrument of subordination shall be necessary to
                    effect the subordination of this Lease to the lien of any
                    such lease, mortgage or deed of trust. In confirmation of
                    such subordination, however, Tenant shall execute promptly
                    any such certificate or subordination agreement that
                    Landlord may request. Tenant hereby constitutes and appoints
                    Landlord as Tenant's attorney-in-fact to execute any such
                    certificate(s) for and on behalf of Tenant, said appointment
                    to be a power coupled with an interest and irrevocable
                    during the Term of this Lease. In the event of any
                    proceeding to terminate any ground or underlying lease, or
                    in the event of any proceeding for the foreclosure of any
                    mortgage or deed of trust to which this Lease is
                    subordinate, the ground lessor, purchaser, assignee or other
                    successor to Landlord's rights, shall have the option to
                    terminate or cancel this Lease; if this Lease is not so
                    terminated or canceled, Tenant shall attorn to the Lessor
                    thereunder or to the purchaser at the foreclosure sale.

                    Upon request and with reasonable notice from Tenant,
                    Landlord shall obtain a nondisturbance agreement on Tenant's
                    behalf from each existing Mortgagee (and any future
                    mortgagees upon request by Tenant) on such Mortgagees's
                    commercially reasonable standard form (and in recordable
                    form) agreeing that such Mortgagee or any purchaser in a
                    foreclosure sale shall recognize and be bound by the terms
                    of this Lease upon a foreclosure or deed in lieu thereof (as
                    long as no Event of Default exists hereunder).

HOLDOVER            23. If Tenant shall remain in the Premises, with the
PROVISIONS          knowledge and written consent of Landlord, after the
                    expiration of the Term of this Lease, or any renewal or
                    extension thereof, Tenant shall become a tenant from month
                    to month at ONE HUNDRED TEN PERCENT (110%) of the monthly
                    rental for the last month of the Lease Term, commencing on
                    the first day next after the Lease Expiration Date. Tenant
                    shall give to Landlord at least THIRTY (30) days written
                    notice of any intention to quit the Premises, and Tenant
                    shall be entitled to THIRTY (30) days written notice to quit
                    except in the event of default hereunder. All other terms
                    and conditions of this Lease shall remain in full force and
                    effect. Provided, however, that in the event that Tenant
                    shall hold over without Landlord's knowledge and consent,
                    then at any time prior to Landlord's acceptance of rent from
                    Tenant as a monthly tenant hereunder, Landlord, at its
                    option, may re-enter and take possession of the Premises
                    without process, or by any legal proceeds in force in the
                    jurisdiction in which the Building is situated.

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                                                                           -----

                                       28
<PAGE>

SUCCESSORS'         24. It is agreed that all rights, remedies and liabilities
OBLIGATION          hereunder given to or imposed upon either of the parties
                    hereto shall extend to their respective heirs, successors,
                    executors, administrators and assigns. This provision shall
                    not be deemed to grant Tenant any right to assign this Lease
                    or to sublet the Premises, except as set forth in Section 7
                    above. Tenant acknowledges Landlord might not be, now or in
                    the future, the owner of the fee interest in the Premises,
                    the Building and/or Land. The term "LANDLORD" as used in
                    this Lease is hereby defined to be only the then current
                    owner or mortgagee in possession of the Premises. In the
                    event of any sale or sales by the then current Landlord
                    hereunder to any party then, from and after the closing of
                    such sale or lease transaction, the Landlord whose interest
                    is thus sold or leased shall be and hereby is completely
                    released and forever discharged from and of all covenants,
                    obligations and liabilities of Landlord hereunder thereafter
                    accruing.

RULES AND           25. The Tenant covenants that the rules and regulations set
REGULATIONS         forth in Exhibit A, attached hereto and incorporated herein
                    by reference, and such other and further rules and
                    regulations as the Landlord may make and furnish to the
                    Tenant, and which in Landlord's judgment are necessary or
                    appropriate for the general well-being, safety, care and
                    cleanliness of the Premises and the Building together with
                    the appurtenances, shall be faithfully kept, observed and
                    performed by Tenant, and by Tenant's agents, servants,
                    employees and guests unless waived in writing by the
                    Landlord. All such rules and regulations shall be enforced
                    in a consistent manner by Landlord against all tenants in
                    the Buildings. Any failure by Landlord to enforce any rule
                    or regulation against any party shall not be deemed a waiver
                    of such rule or regulation or of Landlord's further right to
                    enforce the same.

REPRESENTATIONS,    26. Landlord's Covenants. Landlord covenants that it has the
WARRANTIES          right to make this Lease for the Term aforesaid, and that if
AND                 Tenant shall pay the rent and performs all of the covenants,
COVENANTS           terms, conditions, and agreements of this Lease to be
OF LANDLORD         performed by Tenant, Tenant shall, during the Term, be able
                    to freely, peaceably and quietly occupy and enjoy the fill
                    possession of the Premises without molestation or hindrance
                    by Landlord or any party claiming through or under Landlord,
                    subject to other provisions contained in this Lease.

                    (a) Landlord shall maintain during the term of this Lease,
                    all risk coverage for the Building in the amount of the full
                    replacement value thereof together with comprehensive
                    general liability insurance.

                                                             Initials: /s/ RP.SS
                                                                           -----

                                       29
<PAGE>

                    (b) Landlord represents and warrants to Tenant as follows:
                    To the best of Landlord's knowledge after due inquiry, no
                    governmental regulated hazardous or toxic substances have
                    been used, processed, released, discharged, generated,
                    treated, stored or disposed of on the Premises, the Building
                    or the land upon which the Building is located (the "Land")
                    and no hazardous or toxic substances currently exist on or
                    about the Premises, the Building or the Land and, to the
                    best of Landlord's knowledge, any adjacent property. In the
                    event Landlord becomes aware of any governmental regulated
                    hazardous or toxic substances that have been used,
                    processed, released, discharged, generated, treated, stored
                    or disposed of on the Premises, the Building or the land
                    upon which the Building is located (the "Land"). Landlord
                    shall remove or otherwise contain any such substances within
                    thirty (30) days after Landlord becomes aware of such
                    hazardous or toxic substances.

RESERVATIONS OF     27. Tenant hereby acknowledges that the Landlord retains the
RIGHTS OF ADDRESS   following rights: (i) to change the street address and/or
                    name of the Building and/or name of the Building and/or the
                    arrangement and/or location entrances, passageways, doors,
                    doorways, corridors, elevators, stairs, toilets, or other
                    public parts of the Building and to make improvements,
                    alterations, additions, installations, eliminations and
                    changes to the Building, Land, parking facilities, or any
                    part thereof, provided that such changes do not unreasonably
                    interfere with Tenant's use and occupancy of the Premises or
                    conduct of its business (except in the event of an
                    emergency); (ii) to erect, use, and maintain pipes and
                    conduits in and through the Premises; (iii) to grant to
                    anyone the exclusive right to conduct any particular
                    business or undertaking in the Building; (iv) to install and
                    maintain signs on the Building and/or Land; and (v) have
                    passkeys to the Premises. Landlord may exercise any or all
                    of the foregoing rights without being deemed to be guilty of
                    an eviction, actual, or constructive, or a disturbance or
                    interruption of the business of Tenant or Tenant's use or
                    occupancy of the Premises.

CONSTRUCTION OF     28. Landlord's Standard Work. It is understood and agreed
LEASEHOLD               ------------------------
IMPROVEMENTS        that Tenant will take the Premises in "AS-IS" condition upon
                    commencement of this Lease Agreement. All Leasehold
                    Improvements existing in the Premises upon occupancy of
                    Tenant or made by or for Tenant after commencement of any
                    lease term with Landlord shall remain as the sole property
                    of the Landlord, and in no event shall Tenant remove any
                    Leasehold Improvements from the Premises.

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                                                                           -----

                                       30
<PAGE>

                    Landlord agrees that it will perform a reasonable turnkey
                    build-out for Tenant, at Landlord's sole cost and expense,
                    up to a maximum allowance of EIGHT AND 00/100 DOLLARS
                    ($8.00) PER SQUARE FOOT, providing building standard work
                    using building standard specifications, materials and color
                    selections, in quantities necessary to build-out the
                    Premises substantially in accordance with Tenant's Plans,
                    which plans shall be mutually agreed upon by Landlord and
                    Tenant, and shall be attached hereto and made a part hereof
                    as Exhibit "B".

MECHANIC LIENS      29. Tenant shall not do, or suffer to be done, any act,
                    matter or thing whereby the Premises (or Tenant's interest
                    therein), or any part thereof, may be encumbered by any
                    mechanics' or materialmen's lien and/or any other lien or
                    encumbrance. Tenant shall discharge, within ten (10)
                    business days after the date of filing, any mechanic's, or
                    materialmen's or other liens filed against the Premises, or
                    Tenant interest therein, or any part thereof, purporting to
                    be for work or material furnished, or to be furnished, to
                    Tenant.

PARKING             30. Landlord agrees to provide for the use of Tenant in
                    common with others, a surface parking area adjacent to the
                    Building in which the Demised Premises are located. The
                    Landlord reserves the right to promulgate rules and
                    regulations relating to the use of such surface parking
                    area, including such limitations as may, in the opinion of
                    the Landlord, be necessary and desirable. Tenant and
                    Tenant's employees shall park their vehicles only in those
                    portions of the parking areas designated for employee
                    parking by the Landlord. Further, Tenant and its employees
                    are expressly prohibited from parking in any portion of the
                    parking area designated or marked for visitor parking only.
                    Tenant, shall within FIVE (5) days after taking possession
                    of the Demised Premises, furnish Landlord or its agent with
                    the vehicle license numbers assigned to Tenant's vehicles
                    and the vehicles of Tenant's employees, and shall thereafter
                    notify the Landlord or its agent of any changes within FIVE
                    (5) days after such changes occur. In the event that the
                    Tenant or any of its employees shall park their vehicles in
                    any portion of the parking area other than that portion
                    designated for that purpose, then the Landlord shall have
                    the right, at Landlord's options to assess Tenant a fine or
                    penalty for any such improperly parked vehicle, and/or to
                    have any such improperly parked vehicle towed at Tenant's
                    expense.

                    As an inducement to enter into this Lease Agreement,
                    Landlord agrees to assign TWO (2) parking spaces in the
                    parking lot, of the Building specifically designated for
                    Tenant.

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                                                                           -----

                                       31
<PAGE>

GENDER              31. Feminine or neuter pronouns shall be substituted for the
                    masculine form, and the plural shall be substituted for the
                    singular number, in any place or places herein in which the
                    context may require such substitution or substitutions.
                    Landlord and Tenant, as a matter of convenience, have been
                    referred to in neuter form.

NOTICES             32. All notices required or desired to be given hereunder by
                    either party to the other shall be hand delivered or given
                    by certified or registered mail, first-class postage
                    prepaid, return receipt requested. Notices to the respective
                    parties shall be addressed as follows:

                        To LANDLORD:
                              ANNANDALE FINANCIAL CENTER JOINT VENTURE
                              c/o Southern Management Corporation
                              1950 Old Gallows Road, Suite 600
                              Vienna, VA 22182

                        To TENANT:
                              ONESOFT CORPORATION
                              ATTN:  James McIntyre, TV, President
                              7010 Little River Turnpike, Suite 410
                              Annandale, VA 22003

                    Either party may, by like written notice, designate a new
                    address to which such notices shall be directed.

ESTOPPEL            33. Tenant agrees, at any time and from time to time, upon
CERTIFICATES        not less than FIVE (5) days prior written notice by
                    Landlord, to execute, acknowledge and deliver to Landlord a
                    statement in writing (i) certifying that this Lease is
                    unmodified and in full force and effect (or if there have
                    been modifications, that the Lease is in full force and
                    effect as modified and stating the modification); (ii)
                    stating the dates to which the rent and any other charges
                    hereunder have been paid by Tenant; (iii) stating whether or
                    not to the best knowledge of Tenant, Landlord is in default
                    in the performance of any covenant; (iv) stating the address
                    to which notices to Tenant should be sent; and (v) any other
                    information as may be reasonably required. Any such
                    statement delivered pursuant hereto may be relied upon by
                    any owner of the Building or the Land, any prospective
                    purchaser of the Building or the Land, any mortgagee or
                    prospective mortgagee of the Building or the Land or of
                    Landlord's interest in either, or any prospective assignee
                    of any such mortgagee.

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                                       32
<PAGE>

SECURITY            34. To secure the full faith performance by Tenant of all of
DEPOSIT             the obligations, covenants, conditions and agreements to be
                    fulfilled, kept, observed, and performed by Tenant, Tenant
                    shall tender Landlord the sum of TWO THOUSAND FOUR HUNDRED
                    SIXTY AND 00/100 DOLLARS ($2,460.00) which sum shall be held
                    as a security deposit ("SECURITY DEPOSIT") and applied
                    towards its damages and/or remedies in the event of Tenant's
                    default Landlord's rights against Tenant in the event of
                    Default shall in no way be limited or restricted by this
                    security deposit. Upon the expiration of this Term (or any
                    renewal or extension thereof in accordance with this Lease),
                    Landlord shall, provided that tenant is not in default under
                    the terms hereof, return and pay back such security deposit
                    to tenant, less such portion thereof as Landlord shall have
                    appropriated to cure any default by tenant with respect to
                    any of Tenant's aforesaid obligations, covenants, conditions
                    and agreements and no damages or expenses incurred by
                    Landlord. In the event of any default by Tenant hereunder,
                    Landlord shall have the right, but not the obligation, to
                    apply all or any portion of the Security Deposit to cure
                    such default, in which event, Tenant shall be obligated to
                    promptly deposit with the Landlord the amount necessary to
                    restore the Security Deposit to its original amount. In the
                    event of the sale or transfer of Landlord's interest in the
                    Building, Landlord shall have the right to transfer the
                    Security Deposit to such purchaser or transferee in which
                    event Tenant shall look only to the new Landlord for the
                    return of the Security Deposit and Landlord shall thereupon
                    be released from all liability to Tenant for the return of
                    such Security Deposit.

GOVERNING           35. The parties agree that the laws of the Commonwealth of
LAW                 Virginia shall govern the validity, performance and
                    enforcement of this Lease.

BROKERS             36. Landlord and Tenant each represent and warrant that
                    neither of them has employed any broker to negotiate the
                    terms of this Lease.

WAIVER OF           37. No delay in exercising or failure to exercise any right
BREACH              or power hereunder by Landlord shall impair any such right
                    or shall be construed as a waiver of any breach or default,
                    or as acquiescence thereto. One or more waivers of any
                    covenants, terms or conditions of this Lease by Landlord
                    shall not be construed by the other party as a waiver of a
                    continuing or subsequent breach of the same covenant, term
                    or condition.

                    The consent or approval by Landlord to or of any act by
                    Tenant of a nature requiring consent or render unnecessary
                    consent to or approval of any subsequent similar act No
                    provision of this Lease shall be deemed to have been waived
                    by Landlord, unless such waiver be in writing signed by
                    Landlord.

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                                                                           -----

                                       33
<PAGE>

SEVERABILITY        38. If any term or provision of this Lease or the
OF CLAUSES          application thereof to any person or circumstance shall to
                    any extent be invalid or unenforceable, the remainder of
                    this Lease, or the application of such term or provision to
                    persons or circumstances other than to those as to which it
                    is held invalid or unenforceable, shall not be affected
                    thereby, and each term arid provision of the Lease shall be
                    valid and be enforced to the fullest extent permitted by
                    law.

CAPTIONS FOR        39. The titles of the sections and paragraphs throughout
CONVENIENCE         this Lease are for convenience and reference only, and the
                    words contained therein shall be in no way held to explain,
                    modify, amplify or aid in the interpretation, construction
                    or meaning of the provisions of this Lease.

DUPLICATE           40. This Lease may be executed in one or more counterparts,
COUNTER-PARTS       each of which shall be an original, and all of which shall
AS ORIGINALS        constitute one and the same instrument.

ENTIRE              41. This Lease constitutes the entire agreement. between the
AGREEMENT           parties and no earlier statements or prior written matter
                    shall have any force or effect. Tenant is not relying on any
                    representations or agreements other than those contained-in
                    this Lease. This Lease shall not be modified or canceled
                    except by written instrument executed by both parties.

                         (SIGNATURES ON FOLLOWING PAGE)

                                                             Initials: /s/ RP.SS
                                                                           -----

                                       34
<PAGE>

                 WITNESSETH the following signatures and seals:

WITNESS                                LANDLORD:

                                       ANNANDALE FINANCIAL CENTER
                                         JOINT VENTURE
                                       a Maryland general partnership

/s/ Sabrina Morell                     By:   /s/ Susan M. Scott
---------------------------------         --------------------------------------

                                       Its:  Agent
                                           -------------------------------------

                                       Date: November 14, 1998
                                            -----------------------------------

ATTEST:                                TENANT:

                                       ONESOFT CORPORATION
                                       a Delaware corporation

/s/ Paul Economon                      By:   /s/ Randall Pevin
---------------------------------         --------------------------------------

Corporate Secretary [Seal]             Its:  Vice President
                                           -------------------------------------

                                       Date: October 27, 1998
                                            ------------------------------------

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                                       35
<PAGE>

                                   EXHIBIT "A"
                                   -----------

                     RULES AND REGULATIONS OF THE BUILDING

The Tenant covenants that the following "RULES and REGULATIONS", and such other
and further Rules and Regulations as the Landlord may make and which in the
Landlord's judgement are needful for the general well being, safety, care and
cleanliness of the Premises and the building of which they are a part together
with their appurtenances, shall be faithfully kept, observed and performed by
the Tenant, and by his agents, servants, employees and guests unless waived in
writing by the Landlord.

     a. The sidewalks, entrances, passages, courts, elevators, vestibules,
stairways, corridors or halls or other parts of the Building not occupied by any
tenant shall not be obstructed or encumbered by any tenant or used for any
purpose other than ingress or egress to and from the Premises. Landlord shall
have the right to control and operate the public portions of the Building, and
the facilities furnished for the common use of the tenants, in such manner as
Landlord reasonably deems best for the benefit of the tenants generally. No
tenant shall permit the visit to the Premises of persons in such numbers or
under such conditions as to materially interfere with the use and enjoyment by
other tenants of the entrances, corridors, elevators and other public portions
or facilities of the Building.

     b. No awning or other projections shall be attached to the outside walls of
the building, without the prior written consent of Landlord. Notwithstanding the
existing window coverings, no drapes, blinds, shades, or screens shall be
attached to or hung in, or used in connection with any window or door of the
Premises, without the prior written consent of Landlord. Such awnings,
projections, curtains, blinds, screens or other fixtures must be of a quality,
type, design, and color, and attached in a manner approved by Landlord.

     c. The doors leading to the corridors or main halls shall be kept closed
during business hours except as they may be used to ingress or egress. No
additional locks shall be placed upon any doors of the Premises, nor shall any
changes be made in existing locks or the mechanisms thereof, except that Tenant
shall have the right at its expense to install security locks on all entry doors
and fire doors opening into the Premises, and also on the doors to any offices
within the Premises, provided Tenant at the termination of its occupancy shall
provide Landlord all keys either furnished to, or otherwise procured by Tenant,
and in the event of the loss of any keys so otherwise procured by Tenant, and in
the event of the loss of any keys so furnished, Tenant shall pay to Landlord the
cost to replace. Tenant further agrees that, should Landlord so require, Tenant
will at its expense remove any additional locks which it installed or caused to
be installed, reinstall the original hardware, and repair to Landlord's
reasonable satisfaction any damage to doors or frames. Tenant agrees to give
access upon reasonable request to any such locked area(s).

     d. Tenant shall not construct, maintain, use or operate within the Premises
or elsewhere in the Building of which the Premises form a part or on the outside
of the Building, any equipment or machinery which produces music, sound or noise
which is audible beyond the Premises.
<PAGE>

     e. There shall be no marking, painting, drilling into or in any way
defacing any part of the Premises or the Building with the exception of affixing
wall decorations, shelving and like items within the Premises. No Tenant shall
throw anything out of the doors or windows or down the corridors or stairs.

     f. The employees of the Landlord are prohibited as such from receiving any
packages or other articles delivered to the Building for the Tenant, and should
any such employee receive any such packages or articles, he or she in so doing
shall be the agent of the Tenant and not of the Landlord.

     g. The water and wash closets and other plumbing fixtures shall not be used
for any purposes other than those for which they were constructed, and no
sweepings, rubbish, rags, or other substances shall be thrown therein. All
reasonable costs for damages resulting from any misuse of the fixtures shall be
borne by the Tenant who, in whose servants, employees, agents, visitors, or
licensees, shall have caused same.

     h. No vehicles or animals, except for animals whose function is to assist
disabled persons, of any kind shall be brought into or kept in or about the
Premises or the Building, and no cooking shall be done or permitted by the
Tenant on the demised premises except in kitchens constructed as part of Tenant
Improvements. No Tenant shall cause or permit any objectionable odors to be
produced upon or emanate from the Premises.

     i. Neither Tenant, nor any of Tenant's servants, employees, agents,
visitors or licensees shall at any time bring or keep upon the Premises any
inflammable, combustible or explosive fluid, chemical or substance except normal
and customary office supplies.

     j. Canvassing, soliciting and peddling in the Building is prohibited and
Tenant shall cooperate to prevent the same.

     k. Any person employed by Tenant to do janitorial work within the Premises
must first obtain Landlord's consent and such person shall, while in the
Building and outside of said demised premises, comply with all instructions
issued by the superintendent of the Building.

     l. There shall not be used in any space, or in the public halls of the
Building, either by any tenant or by jobbers or others, in the delivery or
receipt of merchandise, any hand trucks, except those equipped with rubber
tires.

     m. Access plates to under floor conduits must be left exposed. Where carpet
is installed, carpet must be cut around access plates. Electric and telephone
floor distribution boxes must remain accessible at all times.

     n. Tenant shall use reasonable efforts to adjust thermostat, if adjustable,
to the setting which uses the least amount of energy upon leaving the Premises
daily.

     o. Mats, trash, or other objects are not permitted in the public corridors.

     p. Landlord and/or its parking contractor shall have the right to establish
reasonable rules and regulations for the use of all parking facilities at the
Building.

                                       2
<PAGE>

     q. Landlord shall have the right to determine when Tenant may move its
property; i.e., furnishings, files, etc., into or out of the Premises. Tenant
shall request permission from Landlord for any such move, and shall abide by
Landlord's reasonable rules regarding any such move.

     r. Tenant shall purchase and maintain comprehensive public liability and
property damage insurance on the Premises, protecting Landlord and Tenant
against loss, cost, or expense by reason of injury or death to persons or damage
to or destruction of property by reason of the use and occupancy of the Premises
by Tenant and its invitees, such insurance to be carried by reputable companies
and having limits of not less than $1,000,000.00 for injury to or death of any
one person, $1,000,000.00 for each accident and $1,000,000.00 for property
damage.

     s. No tenant shall purchase spring water, ice, coffee, soft drinks, towels
or other like service, from any company or persons whose repeated violations of
the Building regulations have caused, in Landlord's opinion, a hazard or
nuisance to the Building and/or its occupants.

     t. Landlord reserves the right to exclude from the Building at all times
any person who is not known or does not properly identify himself/herself to the
Building management or night watchman on duty. Landlord may at its option,
require all persons admitted to or leaving the Building between the hours of
6:00 P.M. and 8:00 A.M., Monday through Friday, and at all times on Saturdays,
Sundays and legal holidays, to register. Tenant shall be responsible for all
persons for whom he authorizes entry into or exit out of the Building, and shall
be liable to Landlord for all acts of such persons.

     u. The Premises shall not be used for lodging or sleeping or for any
illegal purpose. The Premises shall never, at any time, be used for any
immortal, disorderly, unlawful or hazardous purposes nor for any other purposes
than hereinbefore specified; and will not manufacture any commodity therein.

     v. Landlord shall not maintain suite finishes which are nonstandard, such
as kitchen appliances, wallpaper, special light, etc. However, should the need
for repairs arise, at Tenant's request, Landlord will arrange for the work to be
done at the Tenant's expense. Tenant shall have the right to select a contractor
for said repairs subject however to Landlord's reasonable approval.

     w. No auction sales shall be conducted in the Building without Landlord's
consent.

     x. No tenant shall use any other method of heating than that provided by
the Landlord without the Landlord's consent.

     y. When reasonably necessary to control the climate, and upon request of
Landlord, Tenant shall keep window coverings closed at the appropriate time of
day to-prevent direct solar penetration of the Premises.

     Landlord agrees to advise Tenant in writing of any additions to, deletions
from, or changes in the foregoing Rules and Regulations. In the event that
Tenant is in violation of any Building rule or regulation, Landlord shall notify
Tenant in writing of the same, and shall allow Tenant a reasonable period of
time within which to comply with such rule and regulation. Failure of

                                       3
<PAGE>

Tenant to comply within such period of time shall constitute a material default
under the terms and conditions of this Lease.

                                       4<PAGE>

                                                                   Exhibit 10.16

                                    SUBLEASE

                                     between

                               DOVER CORPORATION,

                                  as Sublessor,

                                       and

                              ONESOFT CORPORATION,

                                  as Sublessee

                          Dated as of February 23, 1999
<PAGE>

                                TABLE OF CONTENTS
                                -----------------

                                                                           Page
                                                                           ----
ARTICLE 1     Definitions..................................................  1
ARTICLE 2     Sublease of the Subleased Premises: Use: Term................  2
ARTICLE 3     Rent/Electricity Charge......................................  3
ARTICLE 4     Incorporation of Master Lease................................  4
ARTICLE 5     Notices......................................................  6
ARTICLE 6     Right of Sublessor to Cure Sublessee's Defaults..............  7
ARTICLE 7     Consents and Approvals of Sublessor..........................  8
ARTICLE 8     Brokerage....................................................  9
ARTICLE 9     Consent of Prime Landlord....................................  9
ARTICLE 10    Insurance; Alterations; Restoration.......................... 10
ARTICLE 11    Notices...................................................... 10
ARTICLE 12    Miscellaneous................................................ 11
<PAGE>

     THIS AGREEMENT OF SUBLEASE (this "Sublease") made as of this 23rd day of
February, 1999, by and between DOVER CORPORATION, a Delaware corporation, having
an address at 280 Park Avenue, New York, New York 10017 (the "Sublessor"), and
ONESOFT CORPORATION, a Delaware corporation, having an address at 7010 Little
River Turnpike, Suite 460, Annandale, Virginia 22003 (the "Sublessee").

                                  WITNESSETH:
                                  ----------

     WHEREAS, the Sublessor is presently the tenant under that certain lease
dated December 20, 1996 (the "Master Lease") by and between Sablons Investors,
Inc., a New York corporation, predecessor in interest to Boston Properties
Limited Partnership, a Delaware limited partnership, as landlord (the "Prime
Landlord"), and the Sublessor, as tenant, covering the entire 34th floor in the
building known as 280 Park Avenue, New York, New York (the "Building"); and

     WHEREAS, the Sublessee desires to sublease from the Sublessor and the
Sublessor is willing to sublease to the Sublessee a portion of the 34th floor
leased under the Master Lease as identified on Exhibit A attached hereto and
                                               ---------
made a part hereof, together with all fixtures, equipment, improvements and
installations attached thereto on the date hereof (collectively, the "Subleased
Premises"), and all the appurtenances, rights and privileges belonging or
relating to the Subleased Premises, or any portion thereof.

     NOW, THEREFORE, in consideration of the premises and other good and
valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, the Sublessor and the Sublessee, for themselves, their successors
and permitted assigns, hereby covenant and agree as follows:

                              ARTICLE 1 Definitions
                              ---------------------

     Section 1.01. Except as otherwise specified or as the context may otherwise
require, the following terms shall have the respective meanings set forth below
for all purposes of this Sublease, and the definitions of such terms are equally
applicable both to the singular and the plural forms thereof:

     Building shall have the meaning set forth in the first WHEREAS clause.
     --------

     Commencement Date shall have the meaning set forth in Section 2.03.
     -----------------

     Electricity Charge shall have the meaning set forth in Section 3.02.
     ------------------

     Fixed Rent means $212,500.00 per annum.
     ----------

     Master Lease shall have the meaning set forth in the first WHEREAS clause.
     ------------

     PMR means Prime Manhattan Realty.
     ---

     Prime Landlord shall have the meaning set forth in the first WHEREAS
     --------------
clause.
<PAGE>

     Security Deposit shall have the meaning set forth in Section 3.04.
     ----------------

     Studley means Julien J. Studley, Inc.
     -------

     Sublease Expiration Date means the day prior to the fifth anniversary of
     ------------------------
the Commencement Date.

     Sublease Interest Rate means fifteen percent (15 %) per annum.
     ----------------------

     Subleased Premises shall have the meaning set forth in the second WHEREAS
     ------------------
clause.

     Term shall have the meaning set forth in Section 2.03.
     ----

             ARTICLE 2 Sublease of the Subleased Premises: Use: Term
             -------------------------------------------------------

     Section 2.01. The Sublessor hereby subleases, and the Sublessee hereby
hires and takes from the Sublessor, the Subleased Premises, subject to the
terms, provisions, covenants and conditions of this Sublease.

     Section 2.02. The Subleased Premises shall be used only for the purposes
permitted by the Master Lease, and for no other use or purpose.

     Section 2.03. The term of this Sublease (the "Term") shall commence on the
day after the Prime Landlord's consent is obtained pursuant to Article 9 hereof
(the "Commencement Date"). The Term shall expire on the Sublease Expiration
Date, unless it shall sooner cease and expire as hereinafter provided. The Term
of this Sublease shall not be extended due to delays in obtaining the Prime
Landlord's consent, or for any other reason.

     Section 2.04. The Sublessee acknowledges that it has inspected the
Subleased Premises and accepts the same in its "as is" condition on the date
hereof, subject to ordinary wear, tear and use between the date hereof and the
Commencement Date, and that the Sublessor shall have no obligation whatsoever to
(a) make any alterations, improvements or repairs, (b) install any fixtures or
equipment or (c) render any services to make the Building or the Subleased
Premises ready or suitable for the Sublessee's use or occupancy. The Sublessee
shall be solely responsible for any cost and expense incurred in connection with
any work or services performed in preparation for the Sublessee's use and
occupancy of the Subleased Premises.

     Section 2.05. If the Master Lease terminates for any reason whatsoever
prior to the date on which this Sublease is scheduled to expire, this Sublease
shall thereupon terminate immediately. The Sublessor shall not be liable to the
Sublessee by reason of any such termination and thereafter shall have no further
obligations of any kind whatsoever to the Sublessee.

     Section 2.06. Upon the scheduled expiration or termination of this
Sublease, or upon any earlier termination of this Sublease, the Sublessee shall
peaceably and quietly leave and surrender to the Sublessor the Subleased
Premises broom clean, in good condition and repair,

                                       2
<PAGE>

ordinary wear and tear excepted. The Sublessee's obligations under this Section
2.06 shall survive the expiration of the Term or any earlier termination of this
Sublease.

     Section 2.07.  If the Sublessor is unable to give possession of the
Subleased Premises on the Commencement Date for any reason whatsoever including,
but not limited to, the continuing possession of any other subtenant or person
or the failure or delay of the Prime Landlord in granting its consent to this
Sublease, the Sublessor shall not be liable for the failure to give such
possession, nor shall such failure be deemed to extend the Term. In such event,
this Sublease shall continue in full force and effect; provided, however, that
Fixed Rent shall abate until the Sublessor gives the Sublessee written notice
that the Subleased Premises are available for occupancy.

                        ARTICLE 3 Rent/Electricity Charge
                        ---------------------------------

     Section 3.01. The Sublessee hereby covenants and agrees to pay to the
Sublessor the Fixed Rent from the Commencement Date until the expiration or
sooner termination of the Term, payable in equal monthly installments of
$17,708.34 in advance on the first day of each month during the Term hereof,
without notice or demand and without abatement, deduction or set-off of any
amount whatsoever. In addition, the Sublessee hereby covenants and agrees to pay
additional rent (as such term is defined in the Master Lease) at the times and
in the manner set forth in the Master Lease as amended by this Sublease. If the
Commencement Date shall not occur on the first day of a month, the first month's
Fixed Rent and additional rent shall be prorated in the manner set forth in the
last sentence of Section 2.1 of the Master Lease.

     Section 3.02. In addition to the Fixed Rent specified in Section 3.01 of
this Sublease, from the Commencement Date the Sublessee shall also pay to the
Sublessor without notice or demand and without abatement, deduction or set-off
of any amount whatsoever, the sum of $2.75 per square foot (or $11,687.50 per
annum) (the "Electricity Charge") for electrical energy consumed on the
Subleased Premises during the Term hereof in equal monthly installments of
$973.96 in advance on the first day of each month during the Term hereof. The
Electricity Charge for the initial month of occupancy shall be pro rated if the
Commencement Date is not the first day of a month. At any time during the Term
at the Sublessor's request, the Sublessee's consumption of electrical energy in
the Subleased Premises shall be determined by a separate survey of the Subleased
Premises (excluding any other space demised under the Master Lease) by a
reputable independent electrical engineer to be selected by the Sublessor whose
fees or charges shall be paid equally by the Sublessor and the Sublessee.
Notwithstanding anything in this Sublease to the contrary, the amount that the
Sublessee shall be obligated to pay for electricity shall be based upon such
survey and similar periodic surveys made from time to time (but not more often
than once a calendar year). The Sublessor shall not in anyway be liable or
responsible to the Sublessee for any loss or damage or expense which the
Sublessee may sustain or incur if either the quantity or character of electric
service is changed or is no longer available or suitable for the Sublessee's
requirements.

     Section 3.03 The Sublessee hereby covenants and agrees to pay any and all
sums required to be paid by the Sublessee pursuant to the terms of this Sublease
to the Sublessor at the address set forth in Article 11, or at such other place
as the Sublessor may designate without notice or demand, abatement, deduction or
set-off of any amount whatsoever in lawful money of the

                                       3
<PAGE>

United States which shall be legal tender for the payment of all debts, public
and private at the time of payment.

     Section 3.04. On the date hereof the Sublessee shall deliver to the
Sublessor either (i) an irrevocable letter of credit in the amount of
$212,500.00, or (ii) a check, subject to collection, in the amount of
$212,500.00 (the "Security Deposit") as security for the Sublessee's performance
of the terms, covenants, conditions and provisions of this Sublease. The letter
of credit shall be issued by a bank and be in form and substance acceptable to
the Sublessor in its sole discretion. The. Sublessor shall have the right,
without notice to the Sublessee, to apply all or any portion of the Security
Deposit to cure any default by the Sublessee under this Sublease. In such event,
the Sublessee shall immediately deposit with the Sublessor an amount equal to
the portion of the Security Deposit so applied so that the Sublessor shall hold
the full amount of the Security Deposit at all times during the Term. The
Sublessee's failure to replenish the Security Deposit shall be an event of
default and any failure of a check delivered as a security deposit to clear
shall be an event of default. Any unapplied portion of the Security Deposit
shall be returned to the Sublessee within thirty (30) days after the expiration
of this Sublease provided that the Sublessee has complied with all of the terms,
covenants, conditions and provisions of this Sublease.

                     ARTICLE 4 Incorporation of Master Lease
                     ---------------------------------------

     Section 4.01. This Sublease is made upon the terms and conditions set forth
in, and is subject and subordinate to (i) the Master Lease and (ii) any
mortgages and ground leases which now or hereafter may be superior to the Master
Lease. A copy of the Master Lease has been delivered to the Sublessee and the
Sublessee hereby acknowledges that it has received, read and examined the Master
Lease and is fully familiar with all of its terms, covenants and provisions.

     Section 4.02. The Sublessor hereby warrants and represents that the Master
Lease is in full force and effect and that the Sublessor, subject to such
consents as are required under the Master Lease, is authorized and empowered to
enter into this Sublease.

     Section 4.03. Except as hereinafter provided in Section 4.05 of this
Sublease, the Sublessor and the Sublessee hereby agree that this Sublease shall
incorporate, and there is hereby incorporated into this Sublease, all of the
terms, covenants, conditions and provisions of the Master Lease with the same
force and effect as if such terms, covenants, conditions and provisions were set
forth herein in full as part of a direct lease from the Sublessor to the
Sublessee, and for the purposes of this incorporation, (a) the term "Tenant" in
the Master Lease means the Sublessee, (b)the term "Landlord" in the Master Lease
means the Sublessor, subject, however, to the limitations set forth in Section
4.05(e) and elsewhere in this Sublease, (c) the term "Demised Premises" in the
Master Lease means the Subleased Premises and (d) the term "Expiration Date" in
the Master Lease means the Sublease Expiration Date. In the event of any
inconsistency between the Master Lease and the specific provisions of this
Sublease, the specific provisions of this Sublease shall govern.

     Section 4.04. This Sublease is subject to, and the Sublessee hereby accepts
this Sublease subject and subordinate to, any amendments and supplements to the
Master Lease hereafter made between Prime Landlord and the Sublessor, provided
that any such amendment or supplement to

                                       4
<PAGE>

the Master Lease which would prevent or adversely affect the use by the
Sublessee of the Subleased Premises in accordance with the terms of this
Sublease, increase the obligations of the Sublessee, or decrease its rights
under this Sublease, shall not be deemed incorporated herein without the express
prior written consent of the Sublessee.

     Section 4.05 (a) For the purposes of this Sublease, the following
provisions of the Master Lease shall be deemed deleted and shall form no part of
this Sublease:

          Section 1.1(f), Section 1.1(g), Section 1.1(h), Section 1.1(j),
          Section 1.1(k), Section 1.1(1), Section 1. 1(u), Section 2. 1(a)
          (except for the last sentence thereof), Section 2.1(b), the last
          sentence of Section 3.2, the third sentence of Section 4.2(d), the
          first sentence of Section 4.9, the last sentence of Section 7.6(a),
          Section 7.7, Section 11.9, Section 11.10, Section 15.1(e), Article 21,
          Section 22.2, Article 25, Article 28, Article 43, Article 44, Exhibit
          B, and Exhibit F.

          (b) For the purposes of this Sublease, the following provisions of the
Master Lease are hereby amended as follows:

              (i)    Section 2.3(d) shall be deleted in its entirety and in lieu
thereof the following language shall be inserted: "Base Tax Year shall mean the
July 1, 1999 to June 30, 2000 Tax Year."

              (ii)   In Section 2.3(f), the words "2.3 percent (2.3%)" shall be
deleted and in lieu thereof the words "52/100 percent (.52%)" shall be inserted.

              (iii)  Section 2.3(h) shall be deleted in its entirety and in lieu
thereof the following language shall be inserted: "Base Wage Rate shall mean the
Wage Rate in effect for the calendar year 1999."

              (iv)   In the first sentence of Section 4.1(b), (a) the words
"Except with respect to Landlord's reimbursement for Tenant's Initial
Construction (as defined and set forth in Article 21 hereof)," shall be deleted
and (b) the next word "all" shall be capitalized.

              (v)    In the second sentence 01 Section 13.1, the words "Except
as expressly provided in Sections 3.2 and 4.2," shall be deleted.

              (vi)   In Section 26.4(a), the third sentence, the fifth sentence,
the sixth sentence and the seventh sentence shall be deleted.

              (vii)  In the first and second sentences of Section 40.1, the
phrase "twenty-five (25)" shall be deleted and in lieu thereof the phrase "six
(6)" shall be inserted.

              (viii) In the second sentence of Section 40.2, the phrase "twelve
(12)" shall be deleted and in lieu thereof the phrase "three (3)" shall be
inserted.

                                       5
<PAGE>

          (c) Wherever it is provided in the Master Lease that the Prime
Landlord has the right to elect to perform any covenant, term or provision
required to be complied with by the tenant thereunder upon default of such
tenant in observing or complying with such covenant, term or provision, such
right shall inure to the benefit of the Sublessor hereunder as well as to the
benefit of the Prime Landlord thereunder.

          (d) Nothing contained herein or in the Master Lease shall be construed
to require the Sublessor to cure any default of the Prime Landlord under the
Master Lease or to bring any action or proceeding or take any steps to enforce
the Sublessor's rights, if any, against the Prime Landlord in respect thereof.

          (e) Without limiting the generality of the foregoing provisions of
this Article 4 and notwithstanding anything in this Sublease or in the Master
Lease to the contrary, the parties hereto hereby agree that the Sublessor shall
not be responsible for furnishing any service or for doing any maintenance or
repairs to the Subleased Premises or for complying with any obligations required
of the Prime Landlord under the Master Lease, and the Sublessee in no event
whatsoever shall be entitled to any allowance, reduction or adjustment of the
Fixed Rent or additional rent payable under this Sublease by reason of the
failure of the Prime Landlord to comply with its obligations, if any, under the
Master Lease. The Sublessee shall look solely to the Prime Landlord for all
services, maintenance, repairs and the performance of all obligations required
to be performed by the Prime Landlord under the Master Lease and shall not under
any circumstances seek nor require the Sublessor to perform any such services,
maintenance, repairs or perform any of said obligations nor shall the Sublessee
make any claim upon the Sublessor for any damages which may arise by reason of
the Prime Landlord's default under the Master Lease or its negligence whether by
omission or commission. In furtherance of the foregoing, the Sublessee does, to
the extent permitted by law, waive any and all causes of action and any right to
bring an action against the Sublessor by reason of any act or omission of the
Prime Landlord under the Master Lease.

          (f) The Sublessee hereby agrees to perform and comply with all of the
terms, provisions, covenants and conditions of the Master Lease required to be
complied with by the tenant thereunder and not to do or suffer or permit
anything to be done which would result in default under or cause the Master
Lease to be terminated or forfeited. The Sublessee shall have no rights in the
Subleased Premises greater than the Sublessor's rights under the Master Lease.

                                ARTICLE 5 Notices
                                -----------------

     Section 5.01. Whenever in the Master Lease a time is specified for the
giving of any notice or the making of any demand by the tenant thereunder, such
time is hereby changed (for the purpose of this Sublease only) by adding two (2)
Business Days thereto, and whenever in the Master Lease a time is specified for
the giving of any notice or the making of any demand by the Prime Landlord
thereunder, such time is hereby changed (for the purpose

                                       6
<PAGE>

of this Sublease only) by subtracting two (2) Business Days therefrom. Whenever
in the Master Lease a time is specified within which the tenant thereunder must
give notice or make a demand following an event, or within which such tenant
must respond to any notice, request or demand previously given or made by the
Prime Landlord thereunder, such time is hereby changed (for the purpose of this
Sublease only) by subtracting two (2) Business Days therefrom. Whenever in the
Master Lease a time is specified within which the Prime Landlord thereunder must
give notice or make a demand following an event, or within which the Prime
Landlord must respond to any notice, request or demand previously given or made
by the tenant thereunder, such time is hereby changed (for the purpose of this
Sublease only) by adding two (2) Business Days thereto. It is the purpose and
intent of the foregoing provisions to provide the Sublessor with time within
which to transmit to the Prime Landlord any notices or demands received from the
Sublessee, and to transmit to the Sublessee any notices or demands received from
the Prime Landlord.

     Section 5.02. Notwithstanding anything contained in any provision of this
Sublease to the contrary, the Sublessee hereby agrees with respect to the
Subleased Premises to comply with and remedy any default under this Sublease
within the period allowed to the Sublessor as tenant under the Master Lease,
even if such time period is shorter than the period otherwise allowed therein
due to the fact that notice of default from the Sublessor to the Sublessee is
given after the corresponding notice of default from the Prime Landlord to the
Sublessor. The Sublessor hereby agrees to forward to the Sublessee, upon receipt
thereof by the Sublessor, a copy of all notices (including, without limitation,
notices of default), requests or demands which relate to the Subleased Premises,
or any portion thereof, received by the Sublessor in its capacity as tenant
under the Master Lease. The Sublessee hereby agrees to forward to the Sublessor,
upon receipt thereof, copies of any notices, requests or demands which relate to
the Subleased Premises, or any portion thereof, received by the Sublessee from
the Prime Landlord or from any governmental authorities.

            ARTICLE 6 Right of Sublessor to Cure Sublessee's Defaults
            ---------------------------------------------------------

     Section 6.01. If the Sublessee shall fail to perform any of the terms,
provisions, covenants or conditions of this Sublease on its part to be
performed, which failure constitutes a default under the Master Lease, then the
Sublessor may, at its option, perform any such term, provision, covenant or
condition, and the full cost and expense incurred shall immediately be due and
owing by the Sublessee to the Sublessor, together with interest thereon at the
Sublease Interest Rate from the date of payment thereof by the Sublessor.

     Section 6.02. If the Sublessee shall default in the performance or
observance of any term, covenant or agreement contained in this Sublease, or in
the Master Lease, as herein incorporated, or breach any representation or
warranty herein, then, in any one or more of such events, if such default shall
not have been remedied after notice given by the Sublessor to the Sublessee and
within the grace period, if any (as such period is modified by the provisions of
Article 5 of this Sublease), provided for under the Master Lease, the Sublessor
shall be entitled to exercise any and all rights and remedies to which the
Sublessor is entitled by law and equity or as are specifically granted to the
Prime Landlord under the Master Lease, which rights and remedies are hereby
incorporated herein and made a part hereof with the same force and effect as
though herein specifically set forth, and the Sublessee shall remain liable as
provided for in the Master Lease.

     Section 6.03. The Sublessee hereby agrees to indemnify the Sublessor and
hold the Sublessor harmless from and against any and all loss, liability,
damage, penalty, cost, claim,

                                       7
<PAGE>

demand, judgment, charge and expense of every kind whatsoever, including
reasonable attorneys' fees, arising out of or incurred in connection with any:

          (a) failure of or by any Sublessee of the Sublessee's interests
hereunder to perform or comply with any and all of the terms, covenants,
conditions and provisions of this Sublease and the Master Lease or breach of any
representation and warranty contained herein;

          (b) use or occupancy by the Sublessee of the Subleased Premises or
from any work of any kind done or omitted to be done, in, on, or about the
Subleased Premises or the Building by the Sublessee or the Sublessee's
employees, contractors, agents, or licensees (including, but not limited to,
construction, alterations, repairs, or similar acts of any kind whatsoever, and
whether or not authorized by this Sublease);

          (c) negligence or willful act or omission of the Sublessee or its
employees, contractors, agents or licensees;

          (d) injuries to persons or property occurring in, on or about the
Subleased Premises or the Building caused by the Sublessee or Sublessee's
employees, contractors, agents, or licensees; and

          (e) any action or proceeding brought against Sublessor by reason of
this Sublease and arising out of any of the circumstances enumerated in
subsections (a) through (d) of this Section 6.03.

     If any action, suit or proceeding shall be brought against the Sublessor in
connection with any matter covered by the indemnity set forth in this Section
6.03, the Sublessee, at the election of the Sublessor and on notice from the
Sublessor, shall defend such action, suit or proceeding at the Sublessee's
expense with counsel approved by the Sublessor.

                  ARTICLE 7 Consents and Approvals of Sublessor
                  ---------------------------------------------

     Section 7.01. The Sublessee hereby agrees that in any case where the
provisions of this Sublease require the consent or approval of the Sublessor
prior to the taking of any action, it shall be a condition precedent to the
taking of such action that the prior written consent or approval of the Prime
Landlord shall have been obtained if the consent of the Prime Landlord must be
obtained under the Master Lease in such cases. The Sublessee hereby agrees that
the Sublessor shall not have any duty or responsibility with respect to
obtaining the consent or approval of the Prime Landlord when the same is
required under the terms of the Master Lease, other than the mere transmission
by the Sublessor to the Prime Landlord of the Sublessee's request for such
consent or approval. If the Prime Landlord shall delay any such consent or
approval, the Sublessor may similarly delay any consent or approval to the
Sublessee. If the Prime Landlord shall refuse such consent or approval, the
Sublessor shall be released from any obligation to grant its consent or
approval, whether or not the Prime Landlord's refusal, in the Sublessee's
opinion, is arbitrary or unreasonable.

                                       8
<PAGE>

                               ARTICLE 8 Brokerage
                               -------------------

     Section 8.01. The Sublessor hereby represents and warrants to the Sublessee
that it has dealt with no brokers, agents or finders other than Studley in
connection with the execution of this Sublease or the transactions contemplated
by this Sublease. The Sublessor agrees to pay the commission due and payable to
Studley pursuant to a separate written agreement between the Sublessor and
Studley.

     Section 8.02. The Sublessee hereby represents and warrants to the Sublessor
that it has dealt with no brokers, agents or finders other than PMR in
connection with the execution of this Sublease or the transactions contemplated
by this Sublease.

     Section 8.03. The Sublessor hereby agrees to indemnify and hold the
Sublessee harmless from and against any commission or fee claim by any person
with whom the Sublessor has dealt with other than Studley and PMR in connection
with the negotiation and execution of this Sublease or any matter whatsoever
pertaining or related thereto. This indemnification shall also cover any and all
expenses which the Sublessee incurs to defend against any such commission or fee
claim including, but not limited to, reasonable attorneys' fees.

     Section 8.04. The Sublessee hereby agrees to indemnify and hold the
Sublessor harmless from and against any commission or fee claim by any person
with whom the Sublessee has dealt with other than Studley in connection with the
negotiation and execution of this Sublease or any matter whatsoever pertaining
or related thereto. This indemnification shall also cover any and all expenses
which the Sublessor incurs to defend against any such commission or fee claim
including, but not limited to, reasonable attorneys' fees.

     Section 8.05. The representations, warranties and indemnifications set
forth in this Article 8 shall survive the expiration or sooner termination of
this Sublease.

                       ARTICLE 9 Consent of Prime Landlord
                       -----------------------------------

     Section 9.01. Notwithstanding anything in this Sublease to the contrary,
the parties hereto hereby expressly acknowledge and agree that this Sublease is
conditioned upon the Sublessor' s obtaining such consents hereto as are required
by the provisions of the Master Lease. Promptly following the execution by the
Sublessee and the Sublessor of this Sublease, the Sublessor hereby agrees to use
commercially reasonable efforts to obtain such consents. The Sublessee hereby
agrees to cooperate in obtaining such consents. The Sublessor shall promptly
notify the Sublessee when such consents have been obtained. If the consent of
the Prime Landlord, or any other consent required by the Master Lease as a
condition to the Sublessor's entering into this Sublease, is not obtained within
sixty (60) days after the execution hereof, either party hereto may cancel this
Sublease at any time prior to the obtaining of said consent(s) by giving written
notice to the other. Upon such cancellation neither party hereto shall have any
further rights or obligations hereunder except such rights and obligations which
expressly survive the termination of this Sublease.

                                       9
<PAGE>

                 ARTICLE 10 Insurance; Alterations; Restoration
                 ----------------------------------------------

     Section 10.01. At its sole cost and expense the Sublessee will obtain and
maintain any and all liability and casualty insurance of any kind whatsoever
with respect to the Subleased Premises which the Sublessor is required to
maintain as tenant under the Master Lease. If the Sublessee fails to maintain
any such insurance, the Sublessor may, at its election, obtain the same and
collect the cost thereof from the Sublessee as additional rent, upon demand,
with interest thereon at the Sublease Interest Rate from the date of such
demand.

     Section 10.02. The Sublessee shall make no alterations, improvements,
decorations, or installations of any kind whatsoever, in or to the Subleased
Premises without the prior written consent of the Sublessor and without the
prior written consent of the Prime Landlord. The Sublessee hereby agrees that
the Sublessee's employment of any contractor, subcontractor, or other person in
connection with the alteration, restoration, improvement or decoration of the
Subleased Premises (or any portion thereof) shall be expressly subject to the
approval of the Prime Landlord and the Sublessor.

     Section 10.03. The Sublessee shall restore the Subleased Premises at the
end of the Term and surrender the same to the Sublessor in the same condition
which existed on the date hereof, reasonable wear and tear excepted.

                               ARTICLE 11 Notices
                               ------------------

     Section 11.01. All notices, requests, demands, elections, consents,
approvals and other communications required or permitted to be given hereunder
shall be in writing (each such, a "notice") and addressed as follows (or to such
other address as either party may by previous written notice have designated):

     If to the Sublessor:
     -------------------

          Dover Corporation
          280 Park Avenue
          New York, New York 10017
          Attention:  Robert G. Kuhbach, Esq.

     with a copy to:

          Coudert Brothers
          1114 Avenue of the Americas
          New York, New York 10036
          Attention:  Gerard V. Hannon, Esq.

                                       10
<PAGE>

     If to the Sublessee:
     -------------------

          OneSoft Corporation
          7010 Little River Turnpike, Suite 460
          Annandale, VA 22003
          Attention:  Paul Economon, Esq.

Any notice under this Sublease shall be deemed to have been given only if
delivered by hand (with receipt), sent by Federal Express (with receipt) or
mailed by first class registered or certified mail (return receipt requested),
postage and fees prepaid.  Each notice delivered by hand shall be deemed given
on the day received or rejected, and each notice delivered by mailing or Federal
Express shall be deemed given three (3) Business Days after mailing or delivery
to said courier.

                            ARTICLE 12 Miscellaneous
                            ------------------------

     Section 12.01. This Sublease shall be governed by and construed in
accordance with the laws of the State of New York, without regard to conflicts
of law provisions.

     Section 12.02. The table of contents and the headings of the various
subdivisions of this Sublease are used for reference only and are not to be
taken as part of this Sublease, or to be used in determining the intent of the
parties, or otherwise affect the meaning of this Sublease. All pronouns shall be
deemed to refer to the masculine, feminine, neuter, singular or plural as the
identity of the person or persons may require.

     Section 12.03. This Sublease shall be binding upon and inure to the benefit
of the parties hereto and their respective heirs, distributees, executors,
administrators, successors and permitted assigns. This Section shall not be
construed as a consent to any assignment or subletting by the Sublessee.

     Section 12.04. No covenant, agreement, term or condition of this Sublease
to be performed or complied with by the Sublessee, and no breach thereof, shall
be waived, altered or modified except by a written instrument executed by the
Sublessor. No waiver of any breach shall affect or alter this Sublease, but each
and every term, covenant, condition and provision of this Sublease shall
continue in full force and effect with respect to any other then existing or
subsequent breach.

     Section 12.05. No agreement to accept any surrender of the Subleased
Premises shall be valid unless in writing and duly executed by the Sublessor and
the Sublessee. Except pursuant to a written agreement duly executed by the
Sublessee and the Sublessor, no act or thing done by the Sublessor or its agents
during the Term shall be deemed an acceptance of a surrender of the Subleased
Premises. No agent or employee of the Sublessor shall have any power to accept
the keys of the Subleased Premises prior to the termination of this Sublease and
delivery of keys to any such agent or employee shall not operate as a
termination of this Sublease or a surrender of the Subleased Premises.

                                       11
<PAGE>

     Section 12.06. This Sublease embodies the entire agreement and
understanding between the parties hereto and supersedes all prior agreements and
understandings relating to the subject matter hereof. This Sublease may not be
modified or amended or any term or provision hereof waived or discharged except
in writing and signed by the party against whom such amendment, -modification,
waiver or discharge is sought to be enforced.

     Section 12.07. This Sublease may be executed in several counterparts, each
of which shall be deemed an original but all of which together shall constitute
one and the same instrument.

     Section 12.08. If any term or provision of this Sublease or the application
thereof to any person or circumstances shall, to any extent, be invalid or
unenforceable, the remainder of this Sublease or the application of such term or
provision to persons or circumstances other than those as to which it is held
invalid or unenforceable shall remain valid and enforceable to the extent
permitted by law.

     Section 12.09. The Sublessee shall from time to time, upon the request of
the Sublessor, execute, deliver and furnish such documents as the Sublessor may
reasonably deem necessary or desirable to (a) correct any errors which may be
contained in this Sublease and (b) fully consummate the transactions
contemplated under this Sublease.

     Section 12.10. The parties hereto do not intend to confer any benefit
hereunder on any person, firm or corporation other than the parties hereto.

     Section 12.11. Time shall be of the essence with respect to the Sublessee's
obligations contained in this Sublease.

     Section 12.12. This Sublease shall not be binding or effective until
properly executed and delivered by the parties hereto.

                                       12
<PAGE>

     IN WITNESS WHEREOF, the parties hereto have caused this Sublease to be duly
executed by their authorized signatories on the day and year first hereinabove
written.

                                        SUBLESSOR

                                        DOVER CORPORATION

                                        By:  /s/ Robert G. Kuhback
                                           -------------------------------------
                                           Name:  Robert G. Kuhback
                                           Title:  Vice President

                                        SUBLESSEE

                                        ONESOFT CORPORATION

                                        By:  /s/ Frederick C. Hawkins, III
                                           -------------------------------------
                                           Name:  Frederick C. Hawkins, III
                                           Title:  Chief Financial Officer

                                       13
<PAGE>

                                    Exhibit A

                               Floor Plan Attached

                                       14

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