SHAREHOLDERS' AGREEMENT


THIS  SHAREHOLDERS'  AGREEMENT (the  "Agreement") is made and entered into as of
this 16th day of August, 1999 by and among Summus,  Ltd., a Delaware corporation
(the "Company"),  High Speed Net Solutions, Inc., a Florida corporation;  Sharon
Stairs;  Ahmad Moradi;  Antonio Bianco;  Joseph Peretta;  Rich,  Bahman & Berger
(CPAs); David Anderson;  Stephen Purkiss;  Kerstin Jawerth; Ron Compton and such
other  shareholders  of the  Company  who  become a party to this  Agreement  in
accordance with the terms hereof (collectively, the "Shareholders").

                                   WITNESSETH:

WHEREAS, the Shareholders currently, or as part of the merger of the Company and
Summus  Technologies,  Inc. (the  "Merger"),  will own certain of the issued and
outstanding shares of capital stock of the Company; and

WHEREAS,  the parties to this Agreement  believe that it is in their mutual best
interests to restrict the sale and transfer of any capital stock of the Company,
thus to insure  continuity  and harmony in the  management  and  policies of the
Company; and

NOW,  THEREFORE,  in  consideration of the foregoing and other good and valuable
consideration,  the receipt of which is hereby acknowledged,  the parties hereto
agree as follows:

                                    ARTICLE I
                                   DEFINITIONS

Unless the context requires otherwise,  capitalized terms used herein shall have
the meaning set forth in the Glossary attached to this Agreement.

                                   ARTICLE II
                               TRANSFER OF SHARES

The provisions of this Agreement shall apply to all Shares  currently issued (or
intended to be issued in the Merger) and which may be issued in the future.

                                   ARTICLE III
                            COMPLIANCE WITH AGREEMENT

During the term of this Agreement,  no Shareholder shall Transfer any Shares now
owned or hereafter  acquired by it,  except as permitted  by, and in  compliance
with,  the terms and  conditions of this  Agreement  and in accordance  with any
Applicable  Laws.  Any purported  Transfer not in compliance  with the terms and
conditions of this Agreement shall be void and of no force and effect.
<PAGE>

                                   ARTICLE IV
                               PERMITTED TRANSFERS
                                       AND
                               LEGEND REQUIREMENTS

         4.1 A  Shareholder  may  Transfer  its  Shares in  accordance  with the
provisions of this  Agreement to any other Person (a "Third  Party");  PROVIDED,
HOWEVER,  that (i) any Transfer (other than Involuntary  Transfers in accordance
with Section 5. 1) shall be for consideration that shall consist of only cash or
Marketable  Securities or any combination thereof, and (ii) no Transfer shall be
allowed until such time as the proposed transferee agrees in writing to be bound
by the terms and conditions of this Agreement.

         4.2 As a  result  of  this  Shareholders  Agreement,  each  certificate
evidencing Shares shall bear the following or a substantially similar legend:

             The  securities  evidenced  hereby  are  subject  to the terms of a
             Shareholders'  Agreement among the Company and the  shareholders of
             the Company.  A copy of the  Shareholders'  Agreement is on file at
             the  office of the  Company  and is  available  upon  request.  The
             Shareholders'   Agreement   provides,   among  other  things,   for
             restrictions on the sale, transfer, pledge,  hypothecation or other
             disposition of, the securities represented by this Certificate. Any
             attempted   sale,   transfer,   pledge,   hypothecation   or  other
             disposition of the securities  represented by this  Certificate not
             in compliance  with the terms and  conditions of the  Shareholders'
             Agreement shall be void and of no force and effect.

                                    ARTICLE V
                         INVOLUNTARY TRANSFER OF SHARES

         5.1  COMPANY'S  OPTION. If an Involuntary Transfer of any of the Shares
owned by any Shareholder  (the  "Transferred  Shares") shall occur,  the Company
shall have the right to purchase some or all of the  Transferred  Shares,  which
right shall be  exercisable  by written  notice given to the  transferee  of the
Transferred  Shares  (the  "Involuntary  Transferee")  and the  Shareholder  who
suffered  the  Involuntary  Transfer  or his estate in the case of his death (in
either case, the "Involuntary Transferor") within thirty (30) days after receipt
by the Company of written notice of the  Involuntary  Transfer (or, in the event
no such notice is received,  thirty (30) days after the Company becomes aware of
the Involuntary  Transfer).  The Company shall provide to each other Shareholder
(a  "Continuing  Shareholder")  (i) a copy of any written  notice of Involuntary
Transfer received by the Company (or, in the event no such notice is received, a
written notice of awareness of any Involuntary  Transfer),  within five (5) days
after the Company becomes aware of the Involuntary Transfer,  and (ii) a copy of
any written notice of exercise given by the Company  pursuant to this Section 5.
1. The failure of the Company to exercise such right within such thirty (30) day
time period  shall be regarded  as a waiver of its right to  participate  in the
purchase of the Transferred Shares.

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<PAGE>

         5.2  CONTINUING  SHAREHOLDERS' OPTION. If the Company does not elect to
purchase  all of the  Transferred  Shares as provided  herein,  each  Continuing
Shareholder  shall have the right to  purchase  any  portion of the  Transferred
Shares for which no such  election  has been made by the  Company  (the  "Excess
Transferred  Shares")  pro  rata  based on the  number  of  Shares  owned by the
Shareholders  which  exercise  the right,  which right shall be  exercisable  by
written notice to the Involuntary  Transferee and Involuntary  Transferor  given
within  forty-five  (45) days after receipt by such  Continuing  Shareholder  of
written  notice of the  Involuntary  Transfer from the Company.  The  exercising
Continuing  Shareholder  shall  also  provide a copy of such  written  notice of
exercise to the  Company and the other  Continuing  Shareholders.  A  Continuing
Shareholder  may also  indicate in such notice,  if it so elects,  its desire to
purchase  additional Excess  Transferred Shares (indicating a maximum number, if
any) if any other Continuing Shareholder does not exercise its right to purchase
up to the full amount of its pro rata share of the Excess Transferred Shares. If
one or more Continuing  Shareholders so elect, the additional Excess Transferred
Shares,  if any, shall be allocated (pro rata if more than one, or less than pro
rata with respect to any such Continuing  Shareholder  requesting a lower number
of Excess Transferred Shares) to such Continuing Shareholder(s).  The failure of
a Continuing  Shareholder to exercise such right within such forty-five (45) day
period shall be regarded as a waiver of its right to participate in the purchase
of the Transferred Shares.

         5.3 PURCHASE PRICE FOR TRANSFERRED SHARES. The purchase price per share
of any Transferred Shares shall be the "fair market value" thereof as determined
by mutual agreement of the Involuntary  Transferee and each party  participating
in such purchase, or if no such agreement can be reached within thirty (30) days
after the termination of the forty-five (45) day period provided in Section 5.2,
the purchase  price shall be  determined in  accordance  with the  provisions of
Section 5.6.

         5.4  TERMS OF PAYMENT OF PURCHASE PRICE TO THE  COMPANY AND  CONTINUING
SHAREHOLDERS.  The Company and the exercising Continuing  Shareholders shall pay
the purchase price for the Transferred Shares in cash; provided,  however,  that
the purchase price payable by the Company or any Continuing Shareholders for the
Transferred Shares of the Involuntary Transferor may be paid twenty-five percent
(25 %)  percent  down  within  thirty  (30)  days  after the  purchase  price is
determined  with the balance to be paid with  interest at the rate of the lesser
of the  Bank of  America  prime  rate as  adjusted  from  time to  time,  or the
applicable federal rate in three (3) equal annual  installments of principal and
interest until paid in full. Notwithstanding the foregoing in no event shall the
amount paid as a down payment be less than the amount of any insurance  proceeds
received by the Company or any  Continuing  Shareholder as a result of the death
of the Involuntary  Transferor.  Until the Transferred Shares have been paid for
in full, the Company and each  exercising  Continuing  Shareholder  shall pledge
back the  Transferred  Shares it  purchases  to the  Involuntary  Transferee  as
collateral  for  payment  pursuant  to a  Security  and  Pledge  Agreement  with
customary  terms and conditions,  as determined in the reasonable  discretion of
the Company.

         5.5 FIRST REFUSAL RIGHTS  SURVIVE.  In the event the provisions of this
Article  V shall be held to be  unenforceable  with  respect  to any  particular
Involuntary Transfer of any Shares, each Continuing  Shareholder and the Company
shall have rights of first refusal if the  Involuntary  Transferee  subsequently
obtains a bona fide offer for and  desires to  Transfer  such  Shares,  and such

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<PAGE>

Shares  shall  otherwise  remain  subject  to the terms and  conditions  of this
Agreement, including this Article V.

         5.6  DETERMINATION  OF FAIR  MARKET  VALUE.  For the  purposes  of this
Article  V,  the  "fair  market  value"  of  the  Transferred  Shares  shall  be
determined, in the absence of mutual agreement, by an investment banking firm or
firm  of  professional   business   evaluators  (the  "Consultant")   reasonably
satisfactory to each party participating in the transaction.  If each such party
shall not agree upon a  Consultant  within the  earliest of (i) thirty (30) days
after the  delivery of the last  applicable  written  notice  from a  Continuing
Shareholder or the Company with respect to such purchase and sale,  (ii) fifteen
(15) days after such parties notify the Company in writing that mutual agreement
on such  Consultant  cannot be  reached,  or (iii)  fifteen  (15) days after the
expiration of the thirty (30) day period  provided in Section 5.3, the Company's
auditors shall select a Consultant. The determination by the Consultant shall be
final and binding  upon all parties to the  purchase  and sale.  The fees of the
Consultant shall be paid by the Company.

         5.7 NO PREJUDICE.  If the Company or any  Shareholder at any time fails
to exercise  its right to  repurchase  in  accordance  with this  Article V, the
Company or such Shareholder  shall in no way be precluded from (i) exercising in
connection  with any  subsequent  Involuntary  Transfer its right to  repurchase
pursuant to this  Article V with  respect to the Shares in question or any other
Shares or (ii) exercising its rights to repurchase  generally in accordance with
the  provisions  of this  Agreement  with  respect to any other  Transfer of any
Shares.

                                   ARTICLE VI
                             RIGHTS OF FIRST REFUSAL

         6.1  RIGHT  OF FIRST  REFUSAL.  Subject  to  Articles  III and IV,  any
Shareholder  which  desires to Transfer all or any of its Shares (the  "Offering
Shareholder")  to any Third  Party  shall  first make an offer (the  "Offer") to
Transfer  the Shares (the  "Offered  Shares") to the Company and, if the Company
does  not  elect to  purchase  all of the  Offered  Shares,  then to each  other
Shareholder (a  "Non-Offering  Shareholder")  pursuant to the provisions of this
Article VI.

         6.2 OFFER TO COMPANY AND OTHER SHAREHOLDERS.  The Offering  Shareholder
shall send written notice of the Offer (the "Offering  Shareholder's Notice") to
the Company and to each Non-Offering  Shareholder within ten (10) days following
receipt of an offer for such Offered  Shares from,  or a making of an offer with
respect  to the  Offered  Shares to, a Third  Party.  In  addition  to any other
information  required to be provided by the Offering Shareholder pursuant to the
immediately  following sentence,  the Offering  Shareholder's Notice shall state
the number of Offered Shares,  the terms and conditions of the Offer,  including
the price  (stating  the  portion in cash and in  Marketable  Securities  or any
combination  thereof) and the name and address of the Third Party (together with
a copy of all  writings  between  the Third Party and the  Offering  Shareholder
establishing  the terms of the offer  between such  parties) and shall include a
description of any related  transactions,  understandings  or relationships or a
statement that there are no such related  items.  The Offer shall be on the same
terms and conditions, as the offer from, or made by the Offering Shareholder to,
the Third Party.

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<PAGE>

         6.3  COMPANY'S  OPTION.  Upon  receipt  of the  Offering  Shareholder's
Notice,  the Company shall have the right to purchase some or all of the Offered
Shares at the price and upon the terms and conditions  specified in such notice;
provided,  however, that the Company shall have the option to match the price by
agreeing  to pay in cash an  amount  equivalent  to any  portion  of such  price
payable in  Marketable  Securities.  Notice of election to purchase  the Offered
Shares  shall be given by the Company to the  Offering  Shareholder  and to each
Non-Offering Shareholder within thirty (30) days after receipt by the Company of
the Offering  Shareholder's  Notice.  The failure of the Company to exercise its
right to purchase the Offered Shares within such thirty (30) day period shall be
regarded as a waiver of its right to  participate in the purchase of the Offered
Shares.

         6.4 NON-OFFERING SHAREHOLDERS' OPTION. If the Company does not elect to
purchase all of the Offered Shares, each of the Non-Offering  Shareholders shall
have the right to purchase  any portion of the Offered  Shares pro rata based on
the number of Shares  owned by the  Non-Offering  Shareholders  who exercise the
right, for which no such election has been made (the "Excess Offered Shares") at
the  price  and  upon  the  terms  and  conditions  specified  in  the  Offering
Shareholder's  Notice;   provided,   however,  that  each  of  the  Non-Offering
Shareholders  shall  have the  option  to match  the  price by paying in cash an
amount equivalent to any portion of such price payable in Marketable Securities.
A Non-Offering  Shareholder's  right to purchase  Excess Offered Shares shall be
exercisable  by written  notice of exercise to the  Offering  Shareholder  given
within forty-five (45) days after receipt of the Offering  Shareholder's Notice.
The  exercising  Non-Offering  Shareholder  shall  also  provide  a copy of such
written  notice  to the  Company  and the  other  Non-Offering  Shareholders.  A
Non-Offering  Shareholder may also indicate in such notice, if it so elects, its
desire to  purchase  additional  Excess  Offered  Shares  (indicating  a maximum
number,  if any) if any other  Non-Offering  Shareholder  does not  exercise its
right to  purchase  up to the full  amount of its pro rata  amount of the Excess
Offered Shares.  If one or more of the  Non-Offering  Shareholders so elect, the
additional  Excess Offered Shares,  if any, shall be allocated (pro rata if more
than  one,  or  less  than  pro  rata  with  respect  to any  such  Non-Offering
Shareholder  requesting  a  lower  number  of  Excess  Offered  Shares)  to such
Non-Offering  Shareholder(s).  The  failure  of a  Non-Offering  Shareholder  to
exercise such right within such  forty-five (45) day period shall be regarded as
a waiver of its right to participate in the purchase of the Offered Shares.

         6.5  TERMS OF SALE TO THE  COMPANY  AND  NONOFFERING  SHAREHOLDER.  The
purchase  price  payable by the Company or any  Nonoffering  Shareholder  of the
Offered Shares of the Offering  Shareholder may be paid twenty-five  percent (25
%) percent  down with the  balance to be paid with  interest  at the rate of the
lesser of the Bank of America  prime rate as adjusted  from time to time, or the
applicable federal rate in three (3) equal annual  installments of principal and
interest until paid in full. Until the Offered Shares have been paid for in full
by the Company and any exercising Non-Offering Shareholder, the Company and each
exercising  Non-Offering  Shareholder  shall  pledge back the Offered  Shares it
purchases to the Offering  Shareholder as collateral  for payment  pursuant to a
Security and Pledge Agreement with customary terms and conditions, as determined
in the reasonable discretion of the Company.

         6.6  SURRENDER  OF  CERTIFICATES.  At such time as the  Company and the
Non-Offering  Shareholders have agreed to purchase, in the aggregate, all of the
Offered  Shares the Offering  Shareholder  shall  surrender  its  certificate(s)

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<PAGE>

representing  the Offered Shares to the Company with duly executed  assignments,
and the purchasers shall concurrently and therewith pay the Offering Shareholder
the purchase price (or appropriate portion thereof) for the Shares.

         6.7  SALE.  The  Offering  Shareholder  may  Transfer,  subject  to the
provisions of this  Agreement,  the Offered  Shares that the Company  and/or the
Non-Offering  Shareholders  do not elect to purchase on the terms and conditions
set forth in the Offering  Shareholder's Notice delivered to the Company and the
Non-Offering Shareholders,  provided that such sale is consummated within ninety
(90) days of the date of the Offering  Shareholder's  Notice. In accordance with
Articles II, III, and IV, the purchasing  Third Party shall agree to be bound by
the terms and  provisions of this  Agreement  before the Company can reflect the
Transfer on its stock transfer records.  If such sale is not consummated  within
such ninety (90) day period,  all of the  restrictions  of this Agreement  shall
again become effective with respect to the Offered Shares.

                                   ARTICLE VII
                                    EXCEPTION

         Notwithstanding  anything  contained in this Shareholders  Agreement to
the contrary,  the shares owned by HSNS may be  transferred  through the sale of
HSNS by the  sale of all of the  outstanding  capital  stock  of HSNS to a third
party so long as the payment  required  under Section 15.2 of the MLA is made to
the  Company in  accordance  with the terms of the MLA (and the other  terms and
conditions  of Section 15.2 of the MLA are met),  and the ownership by the third
party  purchasing  all of the  capital  stock of HSNS  will not have an  adverse
effect on the Company's business, financial condition,  operations or prospects.
In the event of such a transaction,  the shares of the Company shall continue to
remain  subject to the first  refusal  rights  contained  in this  Shareholders'
Agreement. Subject to a confidentiality agreement acceptable to HSNS, HSNS shall
provide  the Company at least 30 days  advance  written  notice of any  intended
transfer in  accordance  with this Section and the Company shall have 15 days to
respond in writing to HSNS as to its specific reasons as to why it believes such
transfer would have an adverse effect on the Company. The burden of proving such
adverse effect shall be on the Company.  The exception contained in this Article
shall not apply to the sale of HSNS to any entity with which  Roger  Dunavant is
an affiliate.

                                  ARTICLE VIII
                       BOARD OF DIRECTORS; REQUIRED VOTING

         8.1 REQUIRED VOTING. Except for HSNS, which shall control the voting of
the  shares  owned by HSNS,  the  Shareholders  agree to vote  their  shares  as
follows:

            (a) BOARD OF DIRECTORS.  The Shareholders agree to vote their shares
         in such manner as to cause  Jawerth and such other  parties as he shall
         select to be elected to the Board of Directors.

            (b) OTHER  MANNERS.  On all matters submitted to a vote at a regular
         or  special  meeting  of  shareholders  of the  Company  or by  written
         consent, such shares shall be voted as determined by Jawerth.

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<PAGE>

            (c) PROXY GRANT.  In connection with this Article VIII, if requested
         at any time by Dr. Jawerth,  all  Shareholders,  other than HSNS, shall
         promptly grant Jawerth an irrevocable  proxy with respect to the voting
         of the shares, to be used in Jawerth's discretion.

                                   ARTICLE IX
                               GENERAL PROVISIONS

         9.1  TERMINATION OF AGREEMENT.  This Agreement shall terminate upon the
occurrence of any one of the following events:

              (a)    The  written  agreement  of the  Company  and  those
Shareholders  holding a majority of the issued and outstanding capital stock;

              (b)    The bankruptcy, receivership, or dissolution of the
Company; or

              (c)    The  consummation of an underwritten public offering of the
Company's Common Stock.

         9.2 NOTICES.  All notices,  requests,  demands and other communications
hereunder  shall be in  writing  and  shall be  delivered  by hand or  mailed by
certified mail, return receipt requested,  first class postage prepaid,  or sent
by Federal  Express or  similarly  recognized  overnight  delivery  service with
receipt acknowledged addressed as follows:

             (a)    If to the Company:

                    Summus, Ltd.
                    2000 Center Point Dr.
                    Suite 2200
                    Columbia, SC 29210

              (b)   If to the Shareholders:

                    As listed in the stock records of the Company.

              (c)   If  delivered  personally,  the  date  on  which  a  notice,
request,  instruction  or document is delivered  shall be the date on which such
delivery is made and, if delivered by mail or by overnight delivery service, the
date on which such notice, request, instruction or document is received shall be
the date of delivery.  In the event any such  notice,  request,  instruction  or
document  is mailed or  shipped  by  overnight  delivery  service  to a party in
accordance   with  this   Section   9.2  and  is   returned  to  the  sender  as
nondeliverable,  then such notice,  request,  instruction  or document  shall be
deemed to have been delivered or received on the fifth day following the deposit
of such notice,  request,  instruction or document in the United States mails or
the delivery to the overnight  delivery  service  provided  that the  delivering
party shall continue to make  reasonable  efforts to deliver the notice by other
commercially reasonable means.

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<PAGE>

(d)Any  party  hereto may change its address  specified  for  notices  herein by
designating a new address by notice in accordance with this Section 9.2.

         9.3   AMENDMENTS.   This  Agreement,   which   constitutes  the  entire
understanding  and agreement among the parties and supersedes all other previous
agreements among the parties, may only be altered,  amended, changed or modified
by  the  written  agreement  of  the  Company  and  those  Shareholders  holding
two-thirds of the issued and outstanding shares of capital stock of the Company.

         9.4 WAIVER.  Any failure on the part of any party hereto to comply with
any of its obligations,  agreements or conditions hereunder may be waived by any
other party to whom such  compliance is owed. No waiver of any provision of this
Agreement shall be deemed, or shall constitute, a waiver of any other provision,
whether or not similar, nor shall any waiver constitute a continuing waiver.

         9.5 BINDING EFFECT.  Subject to the terms and conditions  hereof,  this
Agreement  shall be binding upon and inure to the benefit of the parties  hereto
and their respective heirs, legal  representatives,  executors,  administrators,
successors  and assigns.  This  Agreement  shall not be  assignable by any party
without  the  prior  written  consent  of each  other  party  hereto,  except in
accordance  with the express  terms and  conditions  hereof.  The  Company,  the
Shareholders,  personal  representatives  of any deceased  Shareholder,  and all
other parties bound by this Agreement shall promptly execute and deliver any and
all papers or instruments  necessary or desirable to carry out the provisions of
this Agreement.

         9.6 HEADING,  ETC.  Headings are for convenience only and do not affect
interpretation of this Agreement.  The following rules of  interpretation  apply
unless the context requires otherwise:

             (a)    The singular includes the plural and conversely.

             (b)    A gender includes all genders.

             (c)    Where  a word or  phrase  is  defined,  its other
grammatical  forms  have a corresponding meaning.

             (d)    A  reference  to any  legislation  or to  any  provision  of
any legislation includes any modification or re-enactment of it, any legislative
provision  substituted  for it, and all  regulations  and statutory  instruments
issued under it.

             (e)     A  reference  to  conduct  includes,   without  limitation,
any  omission,  representation,  statement  or  undertaking,  whether  or not in
writing.

         9.7 ENTIRE AGREEMENT.  This Agreement  constitutes the entire agreement
among the  parties  hereto and  supersedes  and  cancels  any prior  agreements,

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representations,  warranties, or communications,  whether oral or written, among
the parties  hereto  relating  to the  transactions  contemplated  hereby or the
subject matter herein.

         9.8  COUNTERPARTS.  This  Agreement  may be  executed  in  two or  more
counterparts,  each of  which  shall be  deemed  an  original,  but all of which
together shall constitute one and the same instrument.

         9.9 NO AGREEMENT UNTIL EXECUTED. This Agreement shall not constitute or
be deemed to evidence a contract or agreement  among the parties  hereto  unless
and until executed by all parties hereto  irrespective of negotiations among the
parties or the exchanging of drafts of this Agreement.

         9.10  SEVERABILITY.  Any term or provision of this  Agreement  which is
invalid or unenforceable in any jurisdiction  shall be ineffective to the extent
of  such  invalidity  or  unenforceability  without  invalidating  or  rendering
unenforceable the remaining terms or provisions  hereof, and any such invalidity
or  unenforceability  in any such  jurisdiction  shall not  invalidate or render
unenforceable  such  term or  provision  in any  other  jurisdiction;  provided,
however,  that any such invalidity or  unenforceability  does not deny any party
hereto any of the basic benefits of the bargain contemplated by this Agreement.

         9.11 CONFLICTS WITH ARTICLES OF INCORPORATION OR BY-LAWS.  In the event
of  any  conflict   between  this  Agreement  and  the  Company's   Articles  of
Incorporation or By-Laws, respectively, the parties will take such action as may
be necessary and appropriate  consistent with Applicable Laws to ensure that the
provisions of this Agreement will prevail.

         9.12 COSTS  OF  SUIT.  In  the  event  any  legal action is required to
enforce or interpret the terms of this Agreement,  the prevailing party shall be
entitled to recover all costs of suit, including reasonable attorneys' fees.

         9.13 INSURANCE.  Any party hereto shall have the right to purchase life
insurance on the life of any Shareholder of the Company to the extent reasonably
necessary to finance any stock purchases provided for hereinabove. In such case,
such  insured  Shareholder  shall  cooperate  fully  by  performing  all  of the
requirements of the life insurer which are necessary conditions precedent to the
issuance of life insurance policies.

         9.14  SPECIFIC  PERFORMANCE.  The  parties  hereby  declare  that it is
impossible  to measure in money the damages  which will accrue to a party hereto
by reason of a failure to perform any of the  obligations  under this Agreement.
Therefore,  if any party  hereto (or its  representative)  shall  institute  any
action or proceeding to enforce the provisions hereof, any person (including the
Company)  against whom such action or  proceeding  is brought  hereby waives the
claim or defense  therein  that such  party or  representative  has an  adequate
remedy at law and such person  shall not urge in any such  action or  proceeding
the claim or defense that such remedy at law exists.

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<PAGE>

         9.15 UNDERWRITING RESTRICTIONS.  In the event the Company undertakes an
underwritten  public offering,  the  Shareholders  agree to restrict the sale or
transfer  of their  shares for a period,  not to exceed  twelve  months from the
initial  closing  of the  offering,  as  agreed  upon  by the  Company  and  the
underwriter.

         IN WITNESS WHEREOF,  the parties hereto have executed this Agreement as
of the day and year first above written.

                                            COMPANY:

                                            SUMMUS, LTD.

                                            By: /s/ Bjorn Jaweth
                                            Its:  President

                                            SHAREHOLDERS:

                                            HIGH SPEED NET SOLUTIONS, INC.

                                            /s/ Michael M. Cimino
                                            Michael Cimino, Chairman


                                            ------------------------
                                            Sharon Stairs


                                            -------------------------
                                            Ahmad Moradi


                                            -------------------------
                                            Antonio Bianco


                                            -------------------------
                                            Joseph Peretta


                                            -------------------------
                                            Rich, Bahman & Berger (CPAS)


                                            -------------------------
                                            David Anderson


                                            -------------------------
                                            Stephen Purkiss


                                            -------------------------
                                            Kerstin Jawerth


                                            -------------------------
                                            Ron Compton


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                                    GLOSSARY

The following definitions apply unless the context requires otherwise:

AGREEMENT shall mean this Shareholders' Agreement.

APPLICABLE LAWS shall mean all applicable (i) statutes,  ordinances or otherwise
legislative  enactments  of the United  States of  America  or other  country or
foreign government,  or of any state or political  subdivision or agency thereof
(including  any  county,  municipal  or other local  subdivisions),  (ii) rules,
regulations,  orders,  permits,  directives or other actions or approvals of any
Regulatory Authority,  and (iii) judgments,  awards, orders,  decrees, writs and
injunctions of any court Regulatory Authority or arbitrator.

COMMON  STOCK shall mean the common  stock,  $.0001 par value per share,  of the
Company.

COMPANY shall mean Summus, Ltd., a Delaware Corporation.

CONTINUING SHAREHOLDER shall have the meaning set forth in Section 5.1.

CONSULTANT shall have the meaning set forth in Section 5.6.

EXCESS OFFERED SHARES shal have the meaning set forth in Section 6.4.

EXCESS TRANSFERRED SHARES shall have the meaning set forth in Section 5.2.

HSNS shall mean High Speed Net Solutions, Inc., a Florida corporation.

INVOLUNTARY TRANSFER shall mean any Transfer, proceeding or action (other than a
Transfer complying with the provisions of Article VI) by or as a result of which
a Shareholder  shall be deprived or divested of any right,  title or interest in
or to any of the Shares,  including without limitation any seizure under levy of
attachment or execution,  any Transfer in connection  with  bankruptcy  (whether
pursuant  to the filing of a voluntary  or any  involuntary  petition  under the
federal  bankruptcy code) or other court  proceeding to a  debtor-in-possession,
trustee in  bankruptcy  or receiver  or other  officer or agency,  any  Transfer
pursuant  to a  separation  agreement  or the entry of a final  court order in a
divorce  proceeding from which there is no further right of appeal, any Transfer
upon or occasioned by the death of any  Shareholder,  or any Transfer to a legal
representative of any Shareholder.

INVOLUNTARY TRANSFEREE shall have the meaning set forth in Section 5.1.

INVOLUNTARY TRANSFEROR shall have the meaning set forth in Section 5.1.

JAWERTH shall mean Dr. Bjorn Jawerth.

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MARKETABLE SECURITIES shall mean investment grade securities freely tradable and
transferable  without  restriction and listed on a nationally  recognized  stock
exchange or quoted on the NASDAQ National Market System.

MLA shall mean the Marketing License Agreement between the Company and HSNS.

NON-OFFERING SHAREHOLDER shall have the meaning set forth in Section 6.1.

OFFER shall have the meaning set forth in Section 6.1.

OFFERED SHARES shall have the meaning set forth in Section 6.1.

OFFERING SHAREHOLDER shall have the meaning set forth in Section 6.1.

OFFERING SHAREHOLDER'S NOTICE shall have the meaning set forth in Section 6.2.

PERSON shall include, but is not limited to, an individual,  a trust, an estate,
a partnership,  an association, a company, a corporation, a sole proprietorship,
a professional corporation or a professional association.

REGULATORY AUTHORITY shall mean any national,  federal, state, county, municipal
or local government,  department, commission, board, agency, taxing authority or
other  governmental,  administrative  or regulatory  body (whether of the United
States of America or any other country or foreign government).

SECURITIES ACT shall mean the Securities Act of 1933, as amended,  and the rules
and   regulations  of  the  Securities  and  Exchange   Commission   promulgated
thereunder.

SHAREHOLDERS shall mean the current shareholders of the Company,  except for Dr.
Jawerth,  and any  other  Person  who  becomes  bound  by the  terms  hereof  in
accordance with the terms hereof.

SHARES  mean any and all  shares of  capital  stock of the  Company  issued  and
outstanding  whether  common stock,  preferred  stock,  or any other type stock,
whether  voting or  nonvoting,  as well as all  shares of  capital  stock of the
Company issuable  pursuant to outstanding  options,  warrants,  other derivative
securities,  convertible  securities or similar  arrangements,  except for those
shares held from time to time by Jawerth.

THIRD PARTY shall have the meaning set forth in Section 4. 1.

TRANSFER  shall  mean any direct or  indirect  (including,  without  limitation,
through the transfer of ownership  of the owner of the shares)  sale,  transfer,
assignment,   gift,   bequest,   exchange  of  property,   conveyance,   pledge,
encumbrance, or any other form of disposition of any right, title or interest in
and to any of the Shares to any Person.

TRANSFERRED SHARES shall have the meaning set forth in Section 5. 1.


                                       12
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