Exhibit D

SHAREHOLDER AGREEMENT

SHAREHOLDER AGREEMENT dated as of March __, 2001, among the person(s) identified
as Shareholder on the signature page hereof ("Shareholder"), Infonautics, Inc.,
a Pennsylvania corporation (the "Company"), and Tucows Inc., a Delaware
corporation ("Tucows").

WHEREAS, on or about the date of the execution and delivery of this Agreement,
certain parties are entering into an Agreement and Plan of Merger (the "Merger
Agreement"), which contemplates a business combination between Tucows and the
Company in a merger transaction to be accomplished through, as currently
contemplated and as may be modified by the parties thereto, (i) the formation of
TAC Acquisition Corporation ("TAC") and (ii) the merger of Tucows with and into
TAC (the "Merger");

WHEREAS, Shareholder is the beneficial owner of record of approximately
1,456,154 shares of Class A Common Stock of the Company (the "Class A Shares,"
and any other shares of common stock or other voting equity securities of the
Company held of record from time to time by the Shareholder, collectively the
"Subject Securities");

WHEREAS, as a condition to Tucows' willingness to enter into the Merger
Agreement, the Company and Tucows are obtaining this Agreement;

WHEREAS, the Shareholder deems it in the best interest of the Company for the
Company to enter into the Merger Agreement; and

WHEREAS, in order to induce Tucows to enter into the Merger Agreement and to
agree to the covenants and agreements set forth therein, Shareholder has agreed
to enter into this Agreement.

NOW, THEREFORE, to induce Tucows to enter into, and in consideration of its
entering into, the Merger Agreement, and for other good and valuable
consideration the receipt and sufficiency of which are hereby acknowledged by
the parties, and in consideration of the premises and the representations,
warranties and agreements herein contained, and intending to be legally bound,
the parties agree as follows:

Restriction on Transfer or Acquisition of Subject Securities
. Except as otherwise specified in Exhibit A hereto, Shareholder shall not (a)
sell, transfer, pledge, assign or otherwise dispose of, or enter into any
contract, option or other arrangement or understanding with respect to the
direct or indirect sale, transfer, pledge, assignment or other disposition of,
any of the Subject Securities to any person other than to Tucows, Company or any
designee of Company, (b) deposit any of the Subject Securities into escrow, a
voting trust or a voting agreement or grant a proxy with respect to any such
Subject Securities, except as provided in this Agreement, or (c) acquire any
additional securities of the Company without the prior written consent of
Company.

Voting Agreement
. Shareholder agrees that, at any annual or special meeting of the shareholders
of the Company and in any action by written consent of the shareholders of the
Company, Shareholder shall vote the Subject Securities (a) in favor of the
Merger, the approval and adoption of the Merger Agreement and all agreements
related to the transactions contemplated by the Merger Agreement, and any
actions related thereto, and (b) against any action or agreement which would
result in a breach of any representation, warranty or covenant of the Company in
the Merger Agreement or which would otherwise frustrate the purposes of, impede,
interfere with or attempt to discourage the Merger, including without limitation
any other merger, consolidation, sale of assets, reorganization,
recapitalization, liquidation or winding up of the Company or any other
extraordinary transaction involving the Company or any matters related to or in
connection therewith. On the date hereof, the Shareholder shall sign and deliver
to Company the proxy in the form set forth in Exhibit B hereto (the "
Irrevocable Proxy
") to permit the Company to implement the voting agreement set forth in this
Section 2. The Shareholder shall, upon request, execute and deliver any
additional documents deemed by Company to be necessary or desirable to complete
and effectuate the Irrevocable Proxy and the provisions of this Agreement.

No Dissenters Rights
. The Shareholder agrees not to exercise any rights (including without
limitation any rights that may exist under the Pennsylvania Business Corporation
Law of 1988, as amended) to demand appraisal or dissenter's rights of any
Subject Securities owned by the Shareholder with respect to the Merger or the
other transactions contemplated by the Merger Agreement.

Representations and Warranties of the Shareholder
. Shareholder hereby represents and warrants to Company as follows:

(a) Authority. This Agreement and the Irrevocable Proxy are valid and binding
agreements of the Shareholder. If the Shareholder is married and the Class A
Shares constitute community property under applicable laws, this Agreement and
the Irrevocable Proxy have been duly authorized, executed and delivered by and
constitute valid and binding agreements of, such Shareholder's spouse. If this
Agreement is being executed in a representative or fiduciary capacity the person
signing this Agreement has full power and authority to enter into and perform
this Agreement and the Irrevocable Proxy.

(b) Shareholder owns beneficially all of the Class A Shares and has good and
marketable title thereto, free and clear of any claims, liens, encumbrances or
security interests whatsoever (other than any created hereby or made to
Sovereign Bank prior to the date hereof). Shareholder does not beneficially own,
or have any existing right to acquire, any securities of the Company other than
the Class A Shares.

(c) Shareholder has the full and unrestricted legal power, authority and right
to enter into, execute and deliver this Agreement and the Irrevocable Proxy
without the consent or approval of any other person and has not entered into any
voting agreement or granted any person any proxy (revocable or irrevocable) with
respect to the Class A Shares (other than this Agreement and the Irrevocable
Proxy).

Representations and Warranties of the Company.
The Company hereby represents and warrants to Shareholder that the Company has
all requisite corporate power and authority to enter into this Agreement and to
consummate the transactions contemplated hereby and thereby, that this Agreement
has been duly executed and delivered by the Company and this Agreement
constitutes the valid and binding obligation of the Company.

Termination
. This Agreement and the Irrevocable Proxy shall terminate upon the earlier to
occur of (a) the effective time of the Merger or (b) the termination of the
Merger Agreement;
provided, however
, that the term applicable to the transfer of Subject Securities specified on
Exhibit A hereto shall terminate as specified in Exhibit A.

No Brokers
. Except for Company's fairness opinion and related services fee payable to
Janney Montgomery Scott, the Shareholder and the Company represent, as to
themselves and their affiliates, that to the best of their knowledge no agent,
broker, investment banker or other firm or person is or will be entitled to any
broker's or finder's fees or any other commission or similar fee in connection
with any of the transactions contemplated by this Agreement and respectively
agree to indemnify and hold the others harmless from and against any and all
claims, liabilities or obligations with respect to any such fees, commissions or
expenses asserted by any person on the basis of any act or statement alleged to
have occurred or been made by such party or any of its affiliates.

Assignment
. Neither this Agreement nor any of the rights, interests or obligations
hereunder shall be assigned by either of the parties without the prior written
consent of the other party. This Agreement will be binding upon, inure to the
benefit of and be enforceable by the parties and their respective successors and
assigns.

General Provisions
.

(a) Specific Performance. The parties hereto agree that if for any reason any
party hereto shall have failed to perform its obligations under this Agreement
or the Irrevocable Proxy, then the party seeking to enforce this Agreement or
the Irrevocable Proxy shall be entitled to specific performance and injunctive
and other equitable relief, and the parties hereto further agree to waive any
requirement for the securing or posting of any bond in connection with the
obtaining of any such injunctive or other equitable relief. This provision is
without prejudice to any other rights or remedies, whether at law or in equity,
that any party hereto may have against any other party hereto for any failure to
perform its obligations under this Agreement or the Irrevocable Proxy.

(b) Expenses. All costs and expenses incurred in connection with this Agreement
and the transactions contemplated hereby shall be paid by the party incurring
such costs and expenses.

(c) Amendments. This Agreement may not be amended except by an instrument in
writing signed by each of the parties hereto.

(d) Notices. All notices, requests, claims, demands and other communications
hereunder shall be deemed to have been duly given when delivered in person, by
facsimile, telegram or telex, or by registered or certified mail (postage
prepaid, return receipt requested), if to the Company, to its address as set
forth on the signature page hereof and, if to Shareholder, to the address set
forth on the signature page hereof.

(e) Descriptive Headings; Definitions. The headings contained in this Agreement
are for reference purposes only and shall not affect in any way the meaning or
interpretation of this Agreement. All capitalized terms used herein but not
defined herein shall have the meaning ascribed to them in the Merger Agreement.

(f) Counterparts. This Agreement may be executed in two or more counterparts,
all of which shall be considered one and the same agreement, and shall become
effective when one or more of the counterparts have been signed by each of the
parties and delivered to the other parties, it being understood that all parties
need not sign the same counterpart.

(g) Entire Agreement. This Agreement (including the exhibits hereto) constitutes
the entire agreement and supersedes all prior agreements and understandings,
both written and oral, among the parties with respect to the subject matter
hereof. This Agreement (including the documents and instruments referred to
herein) is not intended to and shall not be deemed to confer upon any person
other than the parties hereto any rights or remedies hereunder. If any provision
of this Agreement or the Irrevocable Proxy shall be invalid or unenforceable
under applicable law, such provision shall be ineffective to the extent of such
invalidity or unenforceability only, without in any way affecting the remaining
provisions of this Agreement or the Irrevocable Proxy.

(h) Governing Law. This Agreement shall be governed by and construed in
accordance with the laws of the Commonwealth of Pennsylvania, applicable to
contracts made and to be performed in that Commonwealth.

IN WITNESS WHEREOF, the Company has caused this Agreement to be signed by its
respective officer thereunto duly authorized, and Shareholder has signed this
Agreement, all as of the date first written above.

 

INFONAUTICS, INC.

 

By: _____________________________

Title: VP & General Counsel, Secretary

Address: 590 N. Gulph Road
King of Prussia, PA 19406-2800 USA
610-971-8859 (fax)

 

TUCOWS INC.

 

By: _______________________________________

Title: President, CEO

Address: 96 Mowat Avenue
Toronto, Ontario M6K 3M1 Canada
416-531-5584 (fax)

 

SHAREHOLDER:

______________________________

_______________________________________

Witness

Name: Marvin I. Weinberger

 

 

______________________________

_______________________________________

Witness

Name: Fran Solow Weinberger

Address: 630 Penfield Avenue
Havertown, PA 19083-4120

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EXHIBIT A

TRANSFERS OF SUBJECT SECURITIES

The Company agrees that the restrictions on transfer or acquisition of Subject
Securities set forth in Section 1 of this Agreement shall not apply with respect
to the following:

 1. The sale of that number of shares of Class A Common Stock of the Company
    equal to fifty percent (50%) of the number of shares of Class A Common Stock
    of the Company eligible to be sold by the Shareholder pursuant to Rule 144
    under the Securities Act of 1933 during the period commencing two business
    days following the public announcement by the Company (the "Release Date")
    of the execution of the Merger Agreement and terminating three months
    following the Release Date.

    

 2. The sale of that number of shares of Class A Common Stock of the Company
    equal to seventy five percent (75%) of the number of shares of Class A
    Common Stock of the Company eligible to be sold by the Shareholder pursuant
    to Rule 144 under the Securities Act of 1933 during the period commencing
    three months following the Release Date and terminating six months following
    the Release Date.

The Shareholder agrees that any sale of shares of Class A Common Stock pursuant
to Paragraphs 1 and 2 above shall be in compliance with Rule 144 and the
Company's policy regarding insider trading. The Company agrees to use its best
efforts to have all necessary clearances in order for the Shareholder to sell
his shares of Class A Common Stock under Rule 144 made as soon as reasonably
practicable after receipt by the Company, attention Vice President & General
Counsel, Gerard J. Lewis, Jr., of duly executed and completed paperwork as may
be required in order to complete such sale.

In addition, the Company agrees to use its best efforts to file a registration
statement on Form S-3 with the Securities and Exchange Commission as soon as
reasonably practicable upon Shareholder's written request after (a) consummation
of the Merger or (b) any earlier termination of the Merger in accordance with
Paragraph 7(b). Such registration statement shall provide for the registration
of all shares of the Company owned by the Shareholder as a result of the Merger
less any shares previously sold by the Shareholder ("Merger Shares"). If the
Merger is terminated in accordance with Paragraph 7(b), such registration
statement shall provide for the registration of all shares of Company owned by
the Shareholder at the time of registration, less any shares previously sold by
the Shareholder ("Company Shares"). The registration rights granted under this
paragraph shall terminate when the Shareholder is eligible to sell all of the
Merger Shares or Company Shares, as the case may be, pursuant to Rule 144(k).

 

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EXHIBIT B

 

IRREVOCABLE PROXY

EXECUTED March ___, 2001

 

Marvin I. Weinberger ("Shareholder"), being a holder of shares of Class A Common
Stock of Infonautics, Inc. (the "Company") (the "Class A Shares"), does hereby
constitute and appoint such person or persons as the Company shall designate
from time to time (the "Proxy") the true and lawful attorney and proxy of
Shareholder for him and in his name, place and stead, with full power of
substitution, for a term (the "Term") of one year from the date of execution
hereof, to attend and to vote as the proxy of Shareholder, at any and all
meetings of shareholders of the Company or any adjournments thereof, all of the
Class A Shares eligible to vote which are held of record or beneficially, by
Shareholder, on any and all matters, proposals and questions, whether benefiting
the Proxy or Company or not, that may be lawfully considered there, and to
execute any written consents of Shareholder which may be solicited during the
Term, as fully and with the same number of votes and with the same effect as
Shareholder could do if personally present thereat or if personally solicited to
execute such written consents.

Shareholder hereby revokes all proxies heretofore made by him.

Shareholder hereby ratifies all that the Proxy may or shall lawfully do in
voting the Class A Shares in accordance herewith at any such meeting or
adjournment in respect of all matters, proposals and questions that may properly
come before the shareholders for consideration and action.

Shareholder acknowledges that this proxy is coupled with an interest and is
irrevocable.

_______________________________________

Marvin I. Weinberger

 

_______________________________________

Fran Solow Weinberger