<PAGE>   1
                                                                        Ex - 4.4

THIS WARRANT AND THE SECURITIES THAT MAY BE ACQUIRED UPON THE EXERCISE OF THIS
WARRANT HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED
(THE "SECURITIES ACT"), OR UNDER THE PROVISIONS OF ANY APPLICABLE STATE
SECURITIES LAWS, AND MAY NOT BE SOLD, PLEDGED, HYPOTHECATED OR OTHERWISE
TRANSFERRED UNLESS (I) A REGISTRATION STATEMENT WITH RESPECT THERETO IS
EFFECTIVE UNDER THE SECURITIES ACT OR (II) THE COMPANY HAS RECEIVED AN OPINION
OF COUNSEL REASONABLY SATISFACTORY TO THE COMPANY THAT SUCH REGISTRATION IS NOT
REQUIRED.

                            NOVALINK USA CORPORATION

                         CAPITAL STOCK PURCHASE WARRANT

     NovaLink USA Corporation, a Delaware corporation (the "Company"), hereby
certifies that, for value received, Prism Venture Partners I, L.P. ("Holder") is
entitled, subject to the terms set forth below, to purchase from the Company at
any time or from time to time on or after the date hereof and prior to 5:00
P.M., Boston time, on the Expiration Date, the Warrant Number of fully paid and
non-assessable shares of the Venture Financing Security at a price per share
equal to the Conversion Price (the "Purchase Price").

     Capitalized terms not defined when used herein shall have the meanings set
forth in Section 6.

SECTION 1. EXERCISE OF WARRANT.

     1.1. EXERCISE. This Warrant may be exercised by Holder, in whole or in
part, at any time and from time to time by surrender of this Warrant, together
with (i) the form of subscription at the end hereof duly executed by Holder, to
the Company at its principal office, and (ii) payment, by certified or official
bank check payable to the order of the Company or by wire transfer to its
account, in the amount obtained by multiplying the number of shares of Common
Stock for which this Warrant is then being exercised by the Purchase Price then
in effect. In the event the Warrant is not exercised in full, the Company, at
its expense, shall forthwith issue and deliver to or upon the order of Holder a
new Warrant of like tenor in the name of Holder or as Holder (upon payment by
Holder of any applicable transfer taxes) may request, calling in the aggregate
on the face thereof for the number of shares of Venture Financing Security equal
(without giving effect to any adjustment therein) to (i) the Warrant Number
minus (ii) the number of such shares for which this Warrant shall have been
exercised (without giving effect to any adjustment in number as a result of
changes in the Purchase Price called for above).

     1.2 DELIVERY OF STOCK CERTIFICATES. Subject to the terms and conditions of
this Agreement, as soon as practicable after the exercise of this Warrant in
full or in part, the Company at its expense (including, without limitation, the
payment by it of any applicable issue


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taxes) will cause to be issued in the name of and delivered to Holder, or as
Holder (upon payment by Holder of any applicable transfer taxes) may direct, a
certificate or certificates for the number of fully paid and non-assessable
shares of the Venture Financing Security to which Holder shall be entitled on
such exercise, together with any other stock or other securities and property
(including cash, where applicable) to which Holder is entitled upon such
exercise.

     1.3. FRACTIONAL SHARES. This Warrant may not be exercised as to fractional
shares of the Venture Financing Security. In the event that the exercise of this
Warrant, in full or in part, would result in the issuance of any fractional
share of the Venture Financing Security, then in such event Holder shall be
entitled to cash equal to the fair market value of such fractional share as
determined in good faith by the Board of Directors of the Company.

     1.4. COMPLIANCE WITH LAW. This Warrant is subject to all laws, regulations
and orders of any governmental authority that may be applicable hereto and,
notwithstanding any of the provisions hereof, the Holder agrees that the Holder
will not exercise the Warrant nor will the Company be obligated to issue any
shares of stock hereunder if exercise thereof or the issuance of such shares, as
the case may be, would constitute a violation by the Holder or the Company of
any such law, regulation or order or any provision thereof. As a consequence,
the Holder may not be able to exercise this Warrant if it is not an "accredited
investor" as defined in Regulation D promulgated under the Securities Act as of
the time of exercise. The Company shall not be obligated to take any affirmative
action in order to cause the exercise of this Warrant or the issuance of shares
pursuant hereto to comply with any such law, regulation, order or provision.

SECTION 2. ADJUSTMENTS.

     2.1. STOCK DIVIDENDS, SPLITS, ETC. If the Company (i) declares or pays a
dividend on its Common Stock or on the Venture Financing Securities if the
Venture Financing Securities are securities other than Common Stock, such
dividend to be paid in Common Stock or other securities of the Company, (ii)
subdivides its outstanding shares of Common Stock into a greater amount of
Common Stock, or, if the Venture Financing Securities are securities other than
Common Stock, subdivides the Venture Financing Securities into a greater among
of Venture Financing Securities, then, upon exercise of this Warrant, for each
Venture Financing Security acquired, the Holder shall receive, without cost to
the Holder, the total number and kind of securities to which the Holder would
have been entitled had the Holder owned the Venture Financing Securities of
record as of the date the dividend or subdivision occurred.

     2.2 RECLASSIFICATION, EXCHANGE OR SUBSTITUTION. Upon any reclassification,
exchange, substitution, or other event that results in a change in the number
and/or class of the securities issuable upon exercise of this Warrant, the
Holder shall be entitled to receive, upon exercise of this Warrant, the number
and kind of securities and property that the holder would have received for the
Venture Financing Securities if this Warrant had been exercised immediately
before such reclassification, exchange, substitution or other event. Such an
event shall include, without limitation, any automatic conversion of the
outstanding or issuable securities of the Company of the same class or series as
the Venture Financing Securities to Common Stock pursuant to the terms of the
Company's Certificate of Incorporation upon the closing of a registered public


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offering of the Company's Common Stock. The Company or its successor shall
promptly issue to the Holder a new Warrant for such new securities or other
property. The new Warrant shall provide for adjustments which shall be as nearly
equivalent as may be practical to the adjustments provided for in this Article 2
including without limitation, adjustments to the number of securities or
property issuable upon exercise of the new Warrant.

SECTION 3. CERTAIN OBLIGATIONS OF THE COMPANY.

     3.1. RESERVATION OF STOCK. From and after the date as of which the nature
of the Venture Financing Security is known by the Company, the Company covenants
that it will at all times reserve and keep available out of its authorized and
unissued capital stock, solely for the purpose of issue upon exercise of the
purchase rights evidenced by this Warrant, a number of shares of the Venture
Financing Security equal to the number of shares of the Venture Financing
Security issuable hereunder. The Company will from time to time, in accordance
with the laws of the State of Delaware, take action to increase the authorized
amount of its Venture Financing Securities if at any time the number of shares
of the Venture Financing Security authorized but remaining unissued and
unreserved for other purposes shall be insufficient to permit the exercise of
this Warrant.

     3.2. NO VALUATION OR IMPAIRMENT. The Company will not, by amendment of its
Certificate of Incorporation, including, without limitation, amendment of the
par value of its Common Stock, or through reorganization, consolidation, merger,
dissolution, issuance of capital stock or sale of treasury stock (otherwise than
upon exercise of this Warrant) or sale of assets, or by any other voluntary act
or deed, avoid or seek to avoid the material performance or observance of any of
the covenants, stipulations or conditions in this Warrant to be observed or
performed by the Company. The Company will at all times in good faith assist,
insofar as it is able, in the carrying out of all of the provisions of this
Warrant in a reasonable manner and in the taking of all other action that may be
necessary in order to protect the rights of the holder of this Warrant against
dilution in the manner required by the provisions of this Warrant.

     3.3. MAINTENANCE OF OFFICE. The Company will maintain an office where
presentations and demands to or upon the Company in respect of this Warrant may
be made. The Company will give notice in writing to Holder, at the address of
Holder appearing on the books of the Company, of each change in the location of
such office.

SECTION 4. REORGANIZATION, ETC.

     If any reorganization or reclassification of the capital stock of the
Company, or consolidation or merger of the Company with another corporation, or
sale of all or substantially all of its assets to another corporation or other
Person shall be effected, then, as a condition of such reorganization,
reclassification, consolidation, merger or sale, lawful and adequate provision
shall be made whereby Holder shall thereafter have the right to purchase and
receive upon the terms and conditions herein specified and in lieu of the shares
of the Venture Financing Securities of the Company immediately theretofore
purchasable and receivable upon exercise of this Warrant such securities or
property as may be issued or payable with respect to or in


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exchange for a number of outstanding shares of the Venture Financing Securities
equal to the number of shares of the Venture Financing Securities immediately
theretofore purchasable and receivable upon the exercise of this Warrant had
such reorganization, reclassification, consolidation, merger or sale not taken
place, and in any such case appropriate provision shall be made with respect to
the rights and interests of Holder to the end that the provisions hereof
(including, without limitation, provisions for adjustments of the Purchase Price
and of the number of shares purchasable upon the exercise of this Warrant) shall
thereafter be applicable, as nearly as may be, in relation to any securities or
property thereafter deliverable upon the exercise hereof. The Company shall not
effect any such reorganization, consolidation, merger or sale unless, prior to
or contemporaneously with the consummation thereof, the successor corporation
(if other than the Company) resulting from such consolidation or merger or the
corporation or other Person purchasing such assets shall assume by written
instrument executed and delivered to Holder, the obligation to deliver to Holder
such securities or property as, in accordance with the foregoing provisions,
Holder may be entitled to purchase or receive.

SECTION 5. NOTICES OF RECORD DATE.

     In the event of:

          (a)  any taking by the Company of a record of the holders of any class
of securities for the purpose of determining the holders thereof who are
entitled to receive any dividend or other distribution, or any right to
subscribe for, purchase or otherwise acquire any shares of stock of any class or
any other securities or property, or to receive any other right; or

          (b)  any capital reorganization of the Company, any reclassification
of the capital stock of the Company or any transfer of all or substantially all
the assets of the Company to or any consolidation or merger of the Company with
or into any other Person; or

          (c)  any voluntary or involuntary dissolution, liquidation or
winding-up of the Company,

then, and in each such event, the Company will give to Holder a notice
specifying (i) the date on which any such record is to be taken for the purpose
of such dividend, distribution or right, and stating the amount and character of
such dividend, distribution or right, and (ii) the date on which any such
reorganization, reclassification, transfer, consolidation, merger, dissolution,
liquidation or winding-up is to take place, and the time, if any is to be fixed,
as of which the holders of record of the Company's capital stock shall be
entitled to exchange their shares of the Company's capital stock for securities
or other property deliverable on such reorganization, reclassification,
transfer, consolidation, merger, dissolution, liquidation or winding-up. Such
notice shall be mailed at least 10 days prior to the date specified in such
notice on which any such action is to be taken.


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SECTION 6. DEFINITIONS.

     As used herein, the following terms, unless the context otherwise requires,
have the following respective meanings:

     6.1. The term COMMON STOCK means the Company's Common Stock, par value
$.001, and any other securities into which or for which the Common Stock is
converted or exchanged pursuant to a plan of reclassification, reorganization,
consolidation, merger, sale of assets, dissolution, liquidation, or otherwise.

     6.2. The term CONVERSION PRICE shall mean the lessor of (i) the actual
price per share of the Venture Financing Security when sold in the Venture
Financing and (ii) $.497 per share of the Venture Financing Security.

     6.3 The term EXPIRATION DATE shall mean the fifth anniversary of the date
of this Warrant.

     6.4. The term PERSON shall mean an individual, partnership, corporation,
association, trust, joint venture, unincorporated organization or any
government, governmental department or agency or political subdivision thereof.

     6.5. The term VENTURE FINANCING shall mean any venture capital
institutional or other equity security financing for the account of the Company
in which stock of the Company is sold for cash and the aggregate gross proceeds
to be received (or commitments for the amounts to be received) by the Company
equals $3,000,000 (exclusive of amounts received under any note held by the
Holder).

     6.6. The term VENTURE FINANCING SECURITY shall mean the security of the
Company sold to the investors in the Venture Financing.

     6.7. The term WARRANT NUMBER shall mean the number of shares of the Venture
Financing Security obtained by dividing $162,500 by the Conversion Price.

     6.8. The term WARRANT STOCK shall mean any equity security issued upon
exercise of this Warrant.

SECTION 7. REPLACEMENT OF WARRANTS.

     Upon (a) surrender of this Warrant in mutilated form or receipt of evidence
satisfactory to the Company of the loss, theft or destruction of this Warrant
and (b) in the case of any loss, theft or destruction of any Warrant, receipt of
an indemnity agreement or security reasonably satisfactory in form and amount to
the Company, then, in the absence of actual notice to the Company that this
Warrant has been acquired by a bona fide purchaser, the Company, at its expense,
shall execute and deliver, in lieu of this Warrant, a new Warrant identical in
form to this Warrant.


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SECTION 8. REMEDIES.

         The Company stipulates that the remedies at law of the Holder in the
event of any breach or threatened breach by the Company of the terms of this
Warrant are not and will not be adequate, and that such terms may be
specifically enforced by a decree for the specific performance of any agreement
contained herein or by an injunction against a breach of any of the terms hereof
or otherwise.

SECTION 9. TRANSFER.

         This Warrant and the shares of the Venture Financing Security issuable
hereunder shall not be sold, transferred, pledged or hypothecated unless the
proposed disposition is the subject of a Federal currently effective
registration statement under the Securities Act or unless the Company has
received an opinion of counsel, in form and substance reasonably satisfactory to
the Company, to the effect that such registration is not required in connection
with such disposition. Subject to the first sentence of this Section, this
Warrant and all rights hereunder are transferable, in whole or in part, at the
office or agency of the Company by the registered holder thereof in person or by
a duly authorized attorney, upon surrender of this Warrant together with an
assignment hereof properly endorsed. Until transfer hereof on the registration
books of the Company, the Company may treat the existing registered holder
hereof as the owner hereof for all purposes. Any transferee of this Warrant and
any rights hereunder, by acceptance thereof, agrees to assume all of the
obligations of Holder and to be bound by all of the terms and provisions of this
Warrant.

SECTION 10. NOTICES.

         Where this Warrant provides for notice of any event, such notice shall
be given (unless otherwise herein expressly provided) in writing and either (i)
delivered personally, (ii) sent by certified, registered or express mail,
postage prepaid, (iii) telegraphed or (iv) telexed or sent by facsimile
transmission, and shall be deemed given when so delivered personally,
telegraphed, telexed, sent by facsimile transmission (confirmed in writing) or
mailed. Notices shall be addressed, if to Holder, to the address of Holder
appearing in the Company's records or, if to the Company, to its office
maintained pursuant to Section 3.3.

SECTION 11. MISCELLANEOUS.

         This Warrant shall be binding upon the Company and Holder and their
legal representatives, successors and assigns. In case any provision of this
Warrant shall be invalid, illegal or unenforceable, or partially invalid,
illegal or unenforceable, the provision shall be enforced to the extent, if any,
that it may legally be enforced and the validity, legality and enforceability of
the remaining provisions shall not in any way be affected or impaired thereby.
This Warrant and any term hereof may be changed, waived, discharged or
terminated only by a statement in writing signed by the party against which
enforcement of such change, waiver, discharge or termination is sought. This
Warrant shall be governed by, and construed and enforced in accordance with, the
laws of the Commonwealth of Massachusetts without regard to


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its principles of conflicts of laws. The headings in this Warrant are for
purposes of reference only, and shall not limit or otherwise affect any of the
terms hereof. This Warrant shall take effect as an instrument under seal.


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     IN WITNESS WHEREOF, the Company has caused this Warrant to be executed by
its duly authorized officer and its corporate seal to be impressed hereon and
attested by its Secretary.

Dated as of October 9, 1997                      NOVALINK USA CORPORATION


(Corporate Seal)                                 By: /s/ J Radoff
                                                     ------------
                                                     Its:

Attest:

      /s/ Pat Bryant
      --------------
      Secretary


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                              FORM OF SUBSCRIPTION

                        (To be signed only on exercise of
                         Capital Stock Purchase Warrant)

TO: NOVALINK USA CORPORATION

The undersigned, the holder of the within Capital Stock Purchase Warrant, hereby
irrevocably elects to exercise this Capital Stock Purchase Warrant for, and to
purchase thereunder *____ shares of Venture Financing Securities of NOVALINK USA
CORPORATION (the "Company") and herewith makes payment of $       therefor, and
requests that the certificates for such shares be issued in the name of, and
delivered to ______________________, whose address is _________________________.


Dated:                                          ________________________________
                                                (Signature must conform in all
                                                respects to name of Holder as
                                                specified on the face of the
                                                Warrant)


_______________________________________________________________________
                                               (Address)



_________________________
     *Insert here the number of shares (all or part of the number of shares
called for in the Capital Stock Purchase Warrant) as to which the Capital
exercised without making any adjustment for any other stock or other securities
or property or cash that, pursuant to the adjustment provisions of the Common
Stock Purchase Warrant, may be deliverable on exercise.


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                               FORM OF ASSIGNMENT

                        (To be signed only on transfer of
                         Capital Stock Purchase Warrant)

     For value received, the undersigned hereby sells, assigns, and transfers
unto _______________________________________ of _______________________________
the right represented by the within Capital Stock Purchase Warrant to purchase
            shares of Venture Financing Securities of NOVALINK USA CORPORATION
to which the within Capital Stock Purchase Warrant relates, and appoints       ,
             Attorney to transfer such right on the books of NOVALINK USA
CORPORATION with full power of substitution in the premises.


Dated:                                      ____________________________________
                                                  (Signature must conform in all
                                                  respects to name of Holder as
                                                  specified on the face of the
                                                  Warrant)


________________________________________________________________________________
                                                 (Address)



Signed in the presence of:


________________________________________