<PAGE>   1
                                                                EXHIBIT 10.26


                        Exclusive Licensing Agreement


     THIS AGREEMENT is entered into and effective as of July 9, 1997 by and
between DATA-DISK TECHNOLOGY, INC., having offices at 45615 Willow Pond Plaza,
Sterling, Virginia 20184, (hereinafter "Licensor"), and XYBERNAUT CORPORATION,
having offices at 12701 Fair Lakes Circle, Fairfax, Virginia, together with THE
DAVIS GROUP, having offices at (hereinafter "Licensee").

Article 1

     Whereas Licensor has developed and invented certain proprietary technology
relating to the storage of information and covered by U.S. and foreign patent
application Serial Number 081401,779 entitled A SYSTEM FOR PROVIDING PERSONAL
MEMORY DEVICES WHICH CAN BE READ AND WRITTEN TO".

Article 2

     Whereas Licensee desires to obtain a world wide exclusive license for a
specific field of use and other licenses under all of the Licensor's present
and future enhancements to its personal memory device technology including that
of Article 1, hereinafter "Technology";

     NOW, THEREFORE, in consideration of the mutual promises contained herein,
Licensor and Licensee hereby agree as follows;

Article 3

     3.1     Licensor hereby grants to Licensee the exclusive world wide right
and license to use all of Licensor's present and future enhancements to
Licensor's personal memory device Technology on wearable computers subject to
royalties to be determined; and

     3.2     Licensor further grants to Licensee the exclusive right and
license to manufacture, use and sell Technology in Germany and to manufacture
Technology only in Japan subject to royalty agreements to be determined; and

     3.3     Licensor also grants to Licensee the non-exclusive world wide
right and license to make, use and sell Licensor Technology for any use other
than on user supported computers subject to royalties to be determined.

     3.4     All of the above grants of 3.1, 3.2 and 3.3 include the
irrevocable right to Licensee to sub-license third parties subject to royalties
to be determined in each instance.

     3.5     Licensee may sub-license under the grant of 3.3 with the written
approval of Licensor, said approval shall not be unreasonably withheld by
Licensor. In all other grants, i.e., of 3.1 and 3.2, Licensee shall have the
unconditional right to sub-license Technology to third parties of their
choosing subject to royalties to be determined.
<PAGE>   2
Article 4

     In consideration for the ir7evocable licenses of Article 3, Licensee shall
pay Licensor an initial license fee of five million dollars U.S., ($5,000,000
U.S.). This license fee will be paid in one payment within 120 days from the
execution of this agreement by both parties.

Article 5

     This Agreement does not constitute a partnership, joint venture or agency
relationship between Licensor and Licensee. Neither party shall be bound or
become liable because of any representation, misrepresentation, action or
omission of the other party.

Article 6

     8.1     Licensor warrants and represents that it is the sole owner of all
rights, title and interest in Technology and is empowered to enter into this
agreement and grant the rights and licenses of Article 3. Licensor agrees as
part of the consideration for the license fee of Article 4 to assist and act as
a consultant to Licensee in areas related to Technology.

     6.2     Licensor agrees to defend, reimburse and hold Licensee harmless
against any claim, action or judgement against Licensee claiming or alleging
that Technology infringes any United States or foreign patent(s). Licensor will
fully pay all damages, costs, attorney fees or other judgements awarded against
Licensee in any action attributable to said claim, action or judgement.

     6.3     In the event that Technology is determined to infringe 6ne or more
U.S. or foreign patents, Licensor agrees to refund Licensee the license fee of
Article 4 in whole or in part, the amount to be determined by an independent
arbitrator or arbitrators agreeable to both parties. Any further controversies
or disputes between the parties shall be submitted to arbitration in accordance
with the arbitration rules of the American Arbitration Association. The place
of arbitration shall be in the state of Virginia.

Article 7

     This agreement constitutes the entire agreement between the parties and
all prior agreements and understandings both oral and written are superceded by
this agreement. This agreement will be construed and enforced in accordance
with the laws of the Commonwealth of Virginia.

Article 8

     This agreement is binding upon and shall inure to the benefit of any
successors or assigns of the parties hereto. Neither Licensor or Licensee shall
object to a proper transfer or assignment of this agreement by the other party
hereto.
<PAGE>   3
     IN WITNESS WHEREOF, the parties have caused their duly authorized
representatives to execute this agreement.


For Licensor                                     For Licensee
------------                                     ------------

DATA-DISK TECHNOLOGY, INC.                       XYBERNAUT CORPORATION

By: /S/ Thomas Francis Clark                     By: /S/ Edward Newman
    ------------------------                         ------------------

Title:  CEO                                      Title:  President
       ---------------------                            ---------------

Date:   07/09/97                                 Date:   08/13/97
      ----------------------                           ----------------

                                                 THE DAVIS GROUP

                                                 By: /S/ Ed Nixon Davis
                                                     ------------------

                                                 Title:  Principle
                                                        ---------------

                                                 Date:   08/14/97
                                                       ----------------
<PAGE>   4

                        DATA-DISK - XYBERNAUT AGREEMENT
                                    8/29/97


I.       Xybernaut will pay $200K to Data-Disk as follows:
         $ 50K by 8/29/97
         $ 50K by 10/15/97
         $ 50K by 1/1/98
         $ 50K by 2/15/98

II.      Xybernaut receives an exclusive perpetual worldwide license to market
Data-Disk products for personal memory devices in the user-supported computer
marketplace for the life of all Data-Disk's patents, pending and granted
related to such technology.

III.     Xybernaut will either pay Data-Disk a royalty per tag and reader of 6%
of revenue Xybernaut receives for Data-Disk products should Xybernaut be
entitled to manufacture such products as in paragraph IV below, or Xybernaut
shall purchase products from Data-Disk at a mutually determined price with
assurances of Most Favored Nations pricing in all Data-Disk product markets.

IV.      If Data-Disk should cease operation for any reason or declare
bankruptcy then, Lloyd H. Woodward and any other holders of patent SN
08/401,779 and related patents, pending or granted, both USA and foreign, as
well as Data-Disk Technology, Inc., shall grant their rights, titles and
interest to the relevant patents, applications, copyrights, trademarks and know
how covering the Data-Disk technologies to Xybernaut Corporation.

V.       Any merger or change of control affecting Data-Disk will not affect
the above exclusive license assigned to Xybernaut.


Agreed to by:           /S/ Steven Newman        /S/ Thomas Francis Clark
                        -----------------        ----------------------------
Name:                   Steven Newman            Thomas Francis Clark
                        -----------------        ----------------------------
For:                    Xybernaut                Data - Disk Technology, Inc.
                        -----------------        ----------------------------
Date:                   08/29/97                 08/29/97
                        -----------------        ----------------------------
<PAGE>   5
                      EXTENSION TO AGREEMENT DATED 7/9/97

Should such above mentioned agreement not be concluded in the stated timeframe,
then Data-Disk hereby agrees to extend the above agreement and its terms to
Xybernaut, for a period of 9 months from its current expiration date.

Should the above be successfully executed, then any funds expended by Xybernaut
under agreement dated 8/29/97, shall be refunded to Xybernaut.


Agreed to by:           /S/ Steven Newman           /S/ Thomas Francis Clark
                        -----------------           ----------------------------

Name:                   Steven Newman               Thomas Francis Clark
                        -----------------           ----------------------------

For:                    Xybernaut                   Data - Disk Technology, Inc.
                        -----------------           ----------------------------

Date:                   08/29/97                    08/29/97
                        -----------------           ----------------------------
<PAGE>   6
                        DATA DISK - XYBERNAUT AGREEMENT

                                    11/26/97

DataDisk (DD) bringing its technology product to either manufacture by a third
party at production levels, or having Xybernaut close a transaction that can
fund the beginning of manufacture in Germany and/or Japan (and thereby allowing
Xybernaut to pay DD the $5 million fee per the 7/9/97 Exclusive Licensing
Agreement) has taken far longer than originally anticipated. As such,
Xybernaut, while wanting to maintain the original rights as stated in such
Exclusive Licensing Agreement and the DD - Xybernaut Agreement of 8/29/97, can
neither pay the original $5 million license fee per the exclusive licensing
agreement, nor the $200K per the 8/29/97 agreement for exclusive user-supported
marketing rights, within the original timeframes. As such, both parties now
agree to the paying the balance of $200K (8/29/97 Agreement) as follows:

<TABLE>
<CAPTION>
   AMT              DUE BY

   <S>             <C>
   $50K             1/26/97
    25K             4/30/98
    25K             6/30/98
    25K             8/31/98
    25K            10/31/98
</TABLE>

However, all of the above scheduled $150K will be paid in full immediately
either when Xybernaut receives monies from investors to start manufacturing
operations per the exclusive agreement, or when product is available to
Xybernaut at production levels and pricing from a DD authorized manufacturer.

By executing this agreement, Xybernaut and DD both agree that all current
agreements remain in effect exclusive of the new payment terms.

Agreed to by:  /S/ Edward Newman
               --------------------
Name:          E. Newman, President
               --------------------
For:           Xybernaut
               --------------------

Date:          11/26/97
               --------------------
<PAGE>   7

                                   AGREEMENT


1.  Xybernaut(R) and MATRIX agree to cancel the Purchasing Contract between
    Xybernaut Corporation and MATRIX Corporation executed on June 17th, 1997
    and release each other from all commitments and obligations defined in the
    above mentioned contract.

2.  MATRIX agrees to stop production of all Mobile Assistants(R) effective
    11/24/97, and will not restart until or if directed by Xybernaut.

3.  Upon execution of this agreement by MATRIX, Xybernaut will, after deducting
    all previously made payments of $592,900 as a credit pay two thirds of the
    remaining balance of the total payment for the 388 units (or $258,908.50),
    as set forth in the attached schedule. Xybernaut agrees to pay the
    remaining $129,454.25 after Matrix assumes the responsibility for the work
    defined in items number 5, 6, 7, 8, 9, 12, 13, 14. Xybernaut will pay the
    $129,454.25 in a single prorated monthly payment for all units made fully
    functional and pass FCC and UL standards during the same month. The
    prorated payment will be equal to the remaining payment of $129,454.25
    divided by the total number of units or 388 multiplied by the number of
    units completed by Matrix during the month. Xybernaut wilt work with Matrix
    in good faith on issues involving the case for FCC and UL approvals.

4.  Upon execution of this agreement by MATRIX, Xybernaut will pay MATRIX
    $57,500 for NRE and will pay MATRIX an additional $57,500 within five days
    after the compliance by MATRIX with sections 5, 6, 7, 8, 9, 13 and 14 and
    after the product passes FCC (Class A & B) and UL.

5.  By accepting the payment defined in #3 above, MATRIX accepts the
    responsibility and cost of making the units fully functional and pass FCC
    (Class A & B) and UL including the full cost of fixing, repairing,
    reworking and shipping the completed units, except for cost to rework tile
    case.

6.  MATRIX agrees to allow Xybernaut on-site inspection and full access to the
    work described above.

7.  MATRIX agrees to warranty the workmanship and parts of the reworked
    completed units defined above for a period of one year, except for the
    case.

8.  MATRIX agrees to transfer the current manufacturing agreement between
    itself and CBA's, to Xybernaut. MATRIX agrees to secure CBA's agreement on
    this transfer prior to signing this contract. In return, Xybernaut agrees
    to pay and accept the liability and ownership of all part inventories at
    MATRIX and CBA after the following conditions are met.

    8.1  All acceptable, reasonable and documented Inventories of parts for the
    Mobile Assistant will be assumed at the original cost to MATRIX and its
    suppliers. Xybernaut will pay for the parts after receiving full disclosure
    of the actual cost in a verifiable form such as purchase orders, contracts,
    invoices, or canceled check.

    8.2  MATRIX agrees to Show Xybernaut to deal directly with CBA or any
    manufacturer or supplier of Xybernaut's choosing regarding production of
    the units.

    8.3  MATRIX agrees to fully disclose the cast and terms in a verifiable
    form such as official quotes, purchase orders, contracts, invoices, or
    canceled checks of all goods and materials purchased on its behalf by CIBA
    and others. Xybernaut agrees to pay any restocking costs associated with
    returning the existing inventory to suppliers.

    8.4 For the six months from the day of signing this agreement MATRIX'CBA
    agree to assist, at no cost to Xybernaut, in documenting, managing and or
    returning any part of inventory Xybernaut has assumed.
<PAGE>   8
    8.5 The execution of this contract is contingent on the successful transfer
    of the current manufacturing agreement between MATRIX and CIBA with its
    associated costs and terms to an identical agreement between Xybernaut and
    CBA.

9.  MATRIX agrees to fully document the current functional test procedures and
    equipment and to package them in a form transferable to CBA or any other
    manufacturing house of Xybernaut's choosing as a complete package. MATRIX
    also agrees to provide support on time and material basis to transfer the
    packaged functional test defined above to CBA or any other contract
    manufacturing house of Xybernaut's choosing.

10. Xybernaut agrees to pay a royalty to MATRIX of $150.00 for each unit
    manufactured and sold with MATRIX designed ZI-XYBE-MOD1 or XI-XYBE-MOD2
    boards, if these units are manufactured by a party other than MATRIX.

11. MATRIX agrees that all work for Xybernaut and for which Xybernaut paid NRE
    is the property of Xybernaut and as such can not be sold or disclosed to a
    third party without express written permission from Xybernaut. MATRIX
    acknowledges that Xybernaut has the right to demand and receive royalty
    payments for any boards or other parts developed specifically for Xybernaut
    if and when Xybernaut authorizes such a sale as defined above. Xybernaut
    agrees that all preexisting MATRIX intellectual property related to the
    PENTX board and card bus board belongs to MATRIX.  The pro-existing MATRIX
    intellectual property associated with these boards that was utilized in the
    ZI-XYBE-MOD1 arid ZI-XYBE-MOD2 can not be sold or disclosed to a third
    party without express written permission from MATRIX.

12. MATRIX agrees not to sell its products to Xybernaut competitors or to sell
    its products for use in body worn or user supported applications for a
    period of two years after the signing of this agreement. In addition,
    MATRIX agrees not to sell its products for use in wearable computer
    applications for a period of five years after the signing of this
    agreement.

13. MATRIX and CBA agree to immediately deliver all currently available
    technical engineering and manufacturing information and documents as well
    as all part source information to Xybernaut in hardcopy and electronic
    form These documents include design notes, schematic drawings fully
    exploded Costed BOMs, Etch drawings, Nail Assignment Drawings (NAD), film,
    Gerber Files, Qualified Component Listing (QCL). Qualified Vendor Listings
    (QVL) test and quality plans and procedures, etc.

14  It is agreed by MATRIX that its compliance with sections 5, 9, 10 and 11
    includes delivery within fifteen days of a complete Engineering and
    Manufacturing documentation Package f~ Xybernaut's use once there is FCC
    approval that the Mobile Assistant is a FCC certifiable product. These
    documents include design notes, schematic drawings, fully exploded Costed
    BOMs, Etch drawings, Nail Assignment Drawings (NAD), film, Gerber Files,
    Qualified Component Listing (QCL), Qualified Vendor Listings (QVL), test
    and quality plans and procedures, etc.

15. Xybernaut and MATRIX will negotiate in good faith to complete a contract
    specifying work and related development costs for the next-generation
    Mobile Assistant(R) product known as "Matrix II".

16. Xybernaut and MATRIX will negotiate in good faith to complete agreements
    for MATRIX to perform additional services for Xybernaut, which may include
    manufacture of the current and/or next generation Mobile Assistant(R).
    Xybernaut agrees to pay $60,000 upon receiving from Matrix an itemized list
    of satisfactory and reasonable charges for the design of the next
    generation Mobile Assistant(R) product known as "Matrix II" supported by
    documentation.
<PAGE>   9
Agreed and accepted by                      Agreed and accepted by
MATRIX Corporation                          Xybernaut Corporation


By: /S/ David W. Mosier Jr.                 By: /S/ Edward G. Newman
    -----------------------                     --------------------
    David W. Mosier, Jr.                        Edward G. Newman
    President                                   President

Date: 9 December 1997                       Date: 12/09/97
    -----------------------                      --------------------