EXHIBIT 4.9

                              SEPARATION AGREEMENT

     SEPARATION  AGREEMENT (this  "Agreement")  dated as of August 1, 2002 (this
"Agreement") by and between  XYBERNAUT  GMBH, a corporation  organized under the
laws of the  Federal  Republic of Germany  ("GMBH"),  XYBERNAUT  CORPORATION,  a
Delaware  corporation  ("XC";  and  GMBH  and  XC  sometimes  collectively,  the
"Company"), and Mr. Daniel J. Butler ("Butler").

     WHEREAS, Butler is employed by GMBH as the Director of GMBH; and

     WHEREAS,  Butler  and  the  Company  mutually  wish to  terminate  Butler's
employment relationship with GMBH, upon the terms, provisions and conditions set
forth in this Agreement.

     NOW,  THEREFORE,  in consideration  of the covenants set forth herein,  and
other good and valuable  consideration,  the receipt and legal adequacy of which
is hereby acknowledged, the parties agree as follows:

          1. Butler  hereby  represents  and  warrants  to the  Company  that he
understands all of the terms and provisions of this Agreement,  the consequences
of entering into this  Agreement and that Butler is entering into this Agreement
of his own free will,  without any duress,  after having had an  opportunity  to
review and discuss this  Agreement  with legal  counsel of his choosing and such
other advisors as Butler considered appropriate.

          2. Butler's  employment by the Company in all respects shall terminate
by mutual  agreement  of the  parties  as of the date  hereof,  subject  to this
Agreement being effective as of the Effective Date (as hereinafter  defined). As
a result thereof,  Butler  represents and warrants to the Company that as of the
Effective  Date  Butler  will  remove all of his  personal  belongings  from the
Company premises, wherever situated. Except for his personal belongings,  Butler
shall not remove  any  property,  assets,  software  or systems  from any of the
Company's  premises or the Company's  systems,  as  applicable.  In this regard,
Butler will have (i) no right to any unpaid salary or bonuses; (ii) no claim for
vacation leave,  sick leave or similar  accruals,  or for payments on account of
any such  accruals;  (iii) no right to receive any payments or benefits from the
Company,  including under any employee  benefit plans or  arrangements;  (iv) no
vested  right in any pension,  profit  sharing or other  retirement,  savings or
employee  benefit  plan of the  Company;  and (v) no right to  reimbursement  of
expenses  incurred on behalf of the Company or  otherwise,  except to the extent
otherwise  expressly  set forth in this  Agreement.  The only payments to Butler
based upon or related to the  termination of his employment  with GMBH are those
expressly set forth in this Agreement.

          3. (a) Butler  acknowledges  and agrees that the Company has  informed
him that he will receive a severance  benefit if, and only if, he executes  this
Agreement  and  fully  complies  with all of its terms  and  provisions.  Butler
further acknowledges and agrees that he understands that the Company will not be
required to provide  the  severance  benefit  until the  Effective  Date of this
Agreement. Subject to the foregoing, Butler shall receive four (4) months



of his  salary  under  Butler's  current  Employment  Contract  with  GMBH  (the
"Employment  Agreement"),  by being issued 160,264  shares of common stock,  par
value $0.01 per share of XC (the "Common  Stock"),  together  with an additional
8,013 shares of Common Stock, for a total of 168,277 shares of Common Stock (the
"Shares").  This severance  payment should replace and supercede in its entirety
any severance benefit provided for in the Employment Agreement. XC grants Butler
piggyback  registration  rights on the next  registration  statement filed by XC
which presently  anticipates to be in the first two weeks of September 2002 with
respect to all of the Shares.

               (b)  Promptly  following  the  execution  and  delivery  of  this
Agreement,  XC shall  cause the GMBH to pay all  salary  and other  benefits  to
Butler which are payable to him for the period ending on July 31, 2002.

               (c) GMBH shall pay  Butler(euro)601.03  in respect of accrued and
unpaid business expenses.

               (d) If Butler  physically  relocates to the United States, as his
principal  residence  at any time prior to October 31, 2002,  the Company  shall
reimburse  Butler for up to  $10,000 of moving  expenses  upon  presentation  of
appropriate documentation.

          4. In order to induce XC to issue the Shares  pursuant to Section 3(a)
hereof to Butler, Butler hereby represents and warrants to XC as follows:

               (a) Butler is aware of what constitutes an "accredited  investor"
as that term is defined under Regulation D promulgated  under the Securities Act
of  1933,  as  amended  (the  "Securities  Act"),  and  under  applicable  state
securities  laws,  and Butler  represents  and warrants  that is an  "accredited
investor" for purposes of Regulation D and such state securities laws.

               (b) Butler  acknowledges that an investment in the Shares and the
Warrants is a  speculative  investment  and involves a high degree of risk,  and
that XC makes no assurances  whatsoever  concerning  the present or  prospective
value of the Shares.  Butler is able to bear the economic risks of an investment
in the  Shares,  and,  consequently,  without  limiting  the  generality  of the
foregoing, is able to hold the Shares for an indefinite period of time and has a
sufficient net worth to sustain a loss of its entire investment in the Shares in
the event such a loss should occur.

               (c) Butler is  acquiring  the Shares for Butler's own account for
investment  and  not  with a view  to or  for  resale  in  connection  with  any
distribution  of the  Shares.  Butler has not offered or sold any portion of the
Shares and has no present  intention  of  dividing  the Shares with others or of
selling, distributing or otherwise disposing of any portion of the Shares either
currently or after the passage of a fixed or determinable period of time or upon
the occurrence or non-occurrence of any predetermined event or circumstance.

               (d) Butler  understands  that the  issuance of the Shares has not
been registered under the Securities Act and that the Shares have been issued in
reliance upon an


                                       2


exemption  therefrom for non-public limited offerings.  Butler acknowledges that
the Shares constitute "restricted  securities" under the Securities Act and they
may not be sold, transferred, assigned, pledged or otherwise disposed of, except
pursuant  to a  registration  statement  that is  declared  effective  under the
Securities  Act, or an exemption from  registration  under the Securities Act as
determined by XC's legal counsel. Butler further acknowledges and agrees that XC
will place an appropriate  restrictive legend on the certificate for the Shares,
as  applicable,  to comply with the Securities Act and to identify the Shares as
"restricted securities".

               (e) Butler  further  acknowledges  that no United States  federal
agency (including,  without limitation,  the SEC), state agency or other similar
agency or regulatory  authority of any other  country,  has reviewed,  approved,
passed upon or made any recommendation or endorsement regarding XC or the Shares
or the Warrants.

               (f) Butler  acknowledges  that XC is relying on the  accuracy  of
Butler's  representations  and warranties set forth this in Section 4 in issuing
the Shares to Butler.

          5. (a) Butler  acknowledges and agrees that neither this Agreement nor
anything contained in this Agreement  constitutes an admission or acknowledgment
by the Company of any: (i) liability;  (ii)  violation of any federal,  state or
local law,  regulation,  order,  rule or other requirement of law, in each case,
whether  domestic or foreign;  (iii) breach of any contract or other  agreement,
actual or implied;  (iv) commission of any tort; or (v) other civil wrong of any
nature.

             (b) Butler  further  warrants to the Company  that he has  received
payment  of his  salary  and all other  benefits  due him  under the  Employment
Agreement through July 31, 2002.

          6.  Butler  acknowledges  and  agrees  that he  understands  there are
various laws and regulations prohibiting employment  discrimination or otherwise
regulating  employment or claims related to employment  pursuant to which he may
have rights or claims. These laws and regulations  include,  without limitation,
the following:  Title VII of the Civil Rights Act of 1964, as amended, including
the  Equal  Employment  Opportunity  Act of  1972;  the  Age  Discrimination  in
Employment Act of 1967, as amended (the "ADEA"); the Americans with Disabilities
Act of 1990;  the  National  Labor  Relations  Act,  as  amended;  the  Employee
Retirement  Income  Security  Act of 1974,  as amended;  the Civil Rights Act of
1991; the Worker Adjustment and Retraining  Notification Act of 1988; the Family
and Medical  Leave Act; 42 U.S.C.  ss.1981;  all  federal,  state and local laws
regarding human rights,  employment and unemployment  insurance.  Butler further
acknowledges and agrees that he understands there are other statutes and laws of
contract  and tort  that may  relate to his  employment  with  GMBH  and/or  the
termination of Butler's employment with GMBH. BUTLER HEREBY  UNCONDITIONALLY AND
IRREVOCABLY WAIVES AND RELEASES ANY RIGHTS HE MAY HAVE UNDER THESE AND ANY OTHER
LAWS (IN EACH CASE AS NOW IN EFFECT AND ANY SUCCESSORS THERETO),  AND UNDER LAWS
OF CONTRACT AND TORT,  BUT HE DOES NOT INTEND TO WAIVE,  NOR IS HE WAIVING,  ANY
RIGHTS  OR  CLAIMS  THAT MAY ARISE  UNDER  THE ADEA  AFTER THE DATE THAT  BUTLER
EXECUTES THIS AGREEMENT.


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          7. In  consideration  of the  agreements,  covenants  and  obligations
contained herein, the parties mutually release each other as follows:

               (a)  Butler  for  himself  and his  heirs,  estate  and  personal
representatives and each of their respective successors and assigns, does hereby
release and forever discharge the Company, its parent, subsidiaries,  affiliates
and divisions,  and each of their respective  successors and assigns, and all of
their  past and  present  directors,  officers,  representatives,  shareholders,
agents,   employees   and  each  of  their   respective   heirs   and   personal
representatives  of any of them (each a "Company Released Party"),  from any and
all charges,  claims, actions, causes of action, suits and other proceedings and
any  losses,  obligations,  promises,  damages,  judgments,  demands,  costs and
expenses (including, without limitation,  attorneys' fees and expenses) of every
kind, nature and description,  and including,  without limitation,  claims under
contract or tort and claims  arising  out of or relating to Butler's  employment
with GMBH or the  termination  of his  employment  with  GMBH and his  rights or
Options (as hereinafter defined), whether known or unknown, suspected, disclosed
or  undisclosed,  claimed or  concealed,  from the beginning of time through the
date of the  Agreement  which Butler could assert  against any Company  Released
Party, except that nothing herein shall be construed as restricting or releasing
Butler's rights or claims that may arise by virtue of a breach of this Agreement
by the  Company.  If Butler  violates  this  Agreement by filing or bringing any
charge,  claim,  action,  suit or other proceeding  against any Company Released
Party  which is  contrary to the release  granted by this  Section  7(a),  or by
improperly  asserting as a defense the  exception  set forth in the  immediately
preceding  sentence of this Section  7(a), in each case as determined by a court
of competent  jurisdiction,  then in addition to any other remedies which may be
available to any of the Company Released Parties, including, but not limited to,
remedies for breach of  contract,  Butler will pay all of the costs and expenses
(including,  without  limitation,  attorneys' fees and expenses) incurred by any
Company  Released Party in defending or responding  against such charge,  claim,
action, suit or other proceeding brought by Butler or on Butler's behalf.

               (b) In consideration of Butler's relinquishing any and all claims
against the  Company  Released  Parties,  the  Company  does hereby  release and
forever discharge Butler and his successors, assigns, heirs, estate and personal
representatives  (each, a "Butler  Released  Party"),  from any and all charges,
claims,  actions,  causes of action,  suits or other proceedings and any losses,
obligations,   promises,  damages,   judgments,   demands,  costs  and  expenses
(including,  without  limitation,  attorneys'  fees and expenses) of every kind,
nature and description, and including, without limitation, claims under contract
or tort and claims arising out of or relating to Butler's  employment  with GMBH
or the  termination  of his  employment  with GMBH,  whether  known or  unknown,
suspected, disclosed or undisclosed, claimed or concealed, from the beginning of
time through the date of this  Agreement  which the Company could assert against
any Butler  Released  Party,  except that  nothing  herein shall be construed as
restricting  or releasing the Company's  rights or claims that may arise (i) due
any action by Butler which would  constitute fraud or a breach of fiduciary duty
under  applicable law while Butler was employed by GMBH or XC and (ii) by virtue
of a breach of this Agreement by Butler.  If the Company violates this Agreement
by filing or bringing any charge,  claim, action, suit or proceeding against any
Butler  Released Party which is contrary to the release  granted by this Section
7(b), or by improperly  asserting as a defense the exceptions set forth in items
(i) or (ii) of this  Section  7(b),  in each  case as  determined  by a court of
competent  jurisdiction,  then in  addition to all other


                                       4


remedies which may be available to any Butler Released Party, including, but not
limited to,  remedies  for breach of  contract,  the Company will pay all of the
costs and expenses (including, without limitation, attorneys' fees and expenses)
incurred by any Butler Released Party in defending or responding to such charge,
claim,  action,  suit or  other  proceeding  brought  by the  Company  or on the
Company's behalf.

               (c) Butler hereby  acknowledges and agrees that as an employee of
GMBH he was in a confidential  relationship with each of GMBH and XC and has had
access  to  Confidential  Information  of the  Company.  For  purposes  of  this
Agreement,  the term  "Confidential  Information"  shall  mean all  confidential
information  regarding  the  Company,  including,  but not limited to,  customer
lists,  vendor lists,  product lists,  price lists,  product  strategies,  sales
reports,  financial data and reports,  marketing and sales plans, strategies and
procedures,  pricing  strategies,  purchasing and sales strategies,  operational
techniques,  business plans and systems, quality control procedures and systems,
internal control procedures, accounting and reporting systems, special projects,
employee  compensation,  personnel and any other records,  intellectual property
rights and intellectual  property strategies,  applications or other information
which is not in the pubic domain or is otherwise proprietary to the Company.

               (d) Butler agrees that he shall not, directly or indirectly, use,
or disclose to any third party any Confidential Information.  Each of Butler and
the Company  agrees to use their  reasonable  best efforts to keep the terms and
provisions  of this  Agreement  confidential  and not to disclose such terms and
provisions  to any third  party,  except (x) each of Butler and the  Company may
make  disclose  of this  Agreement  and its terms  and  provisions  pursuant  to
applicable subpoena, law or regulation and (y) to their respective legal counsel
and accountants.

               (e) Butler  represents  and warrants  that he has returned to the
Company all  equipment  and other  property  of the  Company and all  documents,
materials,   computer  disks  and  other  materials  that  are  based  upon  any
Confidential  Information or  Proprietary  Processes (and all copies of same) in
his  possession  or  control  (regardless  of the  medium in which  maintained),
including,  but not limited to, all  documents  and other  materials  containing
Confidential Information.

               (f) For the twelve  (12) month  period  following  the  Effective
Date, Butler shall not, directly or indirectly,  employ or solicit to employ for
himself or others any employee of the Company or to solicit any such employee of
any of the  Company to leave such  employee's  employment  or join the employ of
another,  then or at a later time,  except a solicitation  made by Butler for an
entity  formed with XC's  concurrence  to engage in the  business  engaged in by
GMBH.

               (g) It is  expressly  acknowledged  and agreed by Butler that his
obligations  set forth in this  Section 7 were an  inducement  to the Company to
enter into this Agreement and that the scope of the provisions set forth in this
Section  7  are  in  each  case   reasonable  and  necessary  in  light  of  the
circumstances. If, for any reason, any aspect of any provision set forth in this
Section  7 as they  apply  to  Butler  is  determined  by a court  of  competent
jurisdiction,  to be unreasonable,  illegal, invalid or unenforceable,  any such
provision shall, to the


                                       5


fullest extent possible, be modified by the court to the minimum extent required
by applicable law to make the  provisions  legal,  valid and  enforceable to the
fullest  extent  permitted by applicable  law.  Butler hereby  acknowledges  and
agrees that his services  were and continue to be of a unique  character  and he
expressly grants the Company the right to enforce the provisions of this Section
7 through the use of all remedies available at law or in equity,  including, but
not limited to,  obtaining a court order,  an  injunction  (both  permanent  and
temporary) or other  equitable  relief  prohibiting  Butler from  threatening to
breach,  breaching  or  continuing  to breach any  provision  of this Section 7,
without the Company being required to post a bond or other security or prove any
amount of actual damages.

          8. Any options to purchase Common Stock which were previously  granted
to Butler and which are vested as of the date of this  Agreement  shall continue
to be  exercisable  for a  period  of six  (6)  months  from  the  date  of this
Agreement,  regardless of any continuing provision which may be set forth in the
stock option plan under which the Options are issued.

          9.  (a) At the request of the  Company, Butler hereby agrees to afford
GMBH such  assistance  in regard to the business of GMBH with respect to matters
in which he was involved during his employment with GMBH; provided that doing so
does not interfere with Butler's then current employment.

              (b) Butler will not  testify or give  evidence in any forum or in
any action, suit or other proceeding concerning his employment or termination of
employment  with GMBH or  otherwise  relating to the Company or its  business or
activities,  unless  required  by  applicable  subpoena,  law or  regulation  or
requested to do so in writing by the Company.

          10.  Butler agrees not to disparage or denigrate the Company or any of
its officers or directors at any time, whether orally or in writing. The Company
agrees not to disparage or denigrate  Butler at any time,  whether  orally or in
writing.

          11. Each of the parties agrees that this Agreement  shall be deemed to
have been made within the  Commonwealth  of Virginia,  and shall be interpreted,
construed,  governed by and enforced in accordance with and governed by the laws
of the  Commonwealth  of  Virginia,  without  regard  to its  conflicts  of laws
principles.  Each of the parties hereby unconditionally and irrevocably consents
to the  exclusive  jurisdiction  of the courts of the  Commonwealth  of Virginia
located  in  Fairfax  County  and the  Federal  District  Court for the  Eastern
District  of Virginia  with  respect to any action,  suit or any  proceeding  to
enforce this Agreement and waives the right to trial by jury in any such action,
suit or other  proceeding.  This  Agreement  shall be construed and  interpreted
without regard to any presumption  against the Company,  which is the party that
caused this Agreement to be drafted.

          12. Each of Butler and the Company  acknowledges  that this  Agreement
may  not  affect  the  rights  and  responsibilities  of  the  Equal  Employment
Opportunity  Commission  (the  "Commission")  to enforce the ADEA, or be used to
justify  interfering with the protected right of an employee to file a charge or
participate in an investigation or proceeding  conducted by the Commission under
the ADEA.


                                       6


          13. Butler hereby  acknowledges and agrees that he was given a copy of
this  Agreement,  and  that he has had an  opportunity  to and  did  consult  an
attorney of his choosing before signing it and was given a reasonable  period of
time to consider this Agreement prior to its execution by Butler. Butler further
acknowledges that in signing this Agreement,  he has relied only on the promises
written in this Agreement and not on any other promise or representation made by
the Company or any of its  directors  or  officers.  This  Agreement  may not be
modified,   amended,  altered,  waived  or  supplemented  except  by  a  written
instrument executed by each of the parties hereto.

          14. This Agreement shall become  effective (the  "Effective  Date") on
the date the  earlier of (i) the date Butler  releases  any right to revoke this
Agreement or (ii) seven (7) days from the date Butler  receives an executed copy
of this Agreement from the Company.

          15. All notices, demands, consents,  requests,  instructions and other
communications  to be given or delivered or permitted  under or by reason of the
provisions of this Agreement or in connection with the transactions contemplated
hereby shall be in writing and shall be deemed to be  delivered  and received by
the intended recipient as follows: (a) if personally delivered,  on the business
day of such  delivery  (as  evidenced  by the receipt of the  personal  delivery
service),  (b) if mailed first class  international  mail, six (6) business days
after being  mailed,  (c) if delivered by a recognized  international  overnight
courier  service (with all charges having been prepaid),  on the business day of
such delivery (as evidenced by the receipt of the overnight  courier  service of
recognized  standing),  or (d) if delivered by  facsimile  transmission,  on the
business  day of such  delivery  if sent by 6:00  p.m.  in the time  zone of the
recipient,  or if sent after that time, on the next succeeding  business day (as
evidenced  by the  printed  confirmation  of delivery  generated  by the sending
party's telecopier  machine).  All such notices,  demands,  consents,  requests,
instructions and other communications will be sent to the addresses or facsimile
numbers set forth below:

               (a)  if to the Company:

                    Xybernaut Corporation
                    12701 Fair Lakes Circle
                    Fairfax, Virginia 22033
                    Facsimile:  703-631-6734
                    Attn:  H. Jan Roltsch-Anoll, Esq.
                           General Counsel

               with a copy to:

                    Jenkens & Gilchrist Parker Chapin LLP
                    The Chrysler Building
                    405 Lexington Avenue
                    New York, New York  10174
                    Attention:  Martin Eric Weisberg, Esq.
                    Facsimile:  212-704-6288


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               (b) if to Butler:

                   Mr. Daniel J. Butler

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

or to such other address as a party shall have designated by notice given to the
other party pursuant hereto.

          16. This Agreement may not be amended,  modified or waived,  except by
an instrument in writing executed by each of the parties hereto.  This Agreement
sets forth the entire  understanding  and  agreement  between the  parties  with
respect to its subject matter and it supersedes all prior and/or contemporaneous
understandings  and  agreements  with  respect to such subject  matter  (whether
written or oral) all of which are merged herein,, including, without limitation,
the Employment  Agreement;  provided that Section 12 of the Employment Agreement
shall remain in full force and effect.  There are no promises or representations
between the parties, except for those which are expressly set forth herein.

          17. This Agreement may be executed in separate  counterparts,  each of
which  shall be an  original,  but all of  which,  when  taken  together,  shall
constitute  one and the same  instrument.  This  Agreement  may be  executed  by
facsimile  signature which will constitute valid and enforceable  signatures for
all purposes.

     IN WITNESS  WHEREOF,  the parties have caused this Agreement to be executed
as of the date first written above.


                                        XYBERNAUT GMBH


                                        By:
                                           -------------------------------------
                                           Name:
                                           Title:


                                        XYBERNAUT CORPORATION

                                        By:
                                           -------------------------------------
                                           Name:
                                           Title:



                                        ----------------------------------------
                                        Daniel J. Butler