Document:

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                                                                   EXHIBIT 10.80

This Warrant and the rights represented hereby shall not be transferable at any
time unless (i) a registration statement under the Securities Act of 1933, as
amended, shall be in effect with respect to this Warrant or the Shares issuable
hereunder at such time, or (ii) the transfer is made in compliance with the
provisions of Section 5.

Number:                                                           50,000  Shares

                                    WARRANT
                              TO PURCHASE SHARES
                                      OF
                             TIPPERARY CORPORATION

     This certifies that, for value received, Jeff T. Obourn, an individual
residing in Greenwood Village, Colorado ("Obourn"), or his registered assigns,
is entitled to purchase from TIPPERARY CORPORATION, a Texas corporation (the
"Company"), fifty thousand (50,000) Shares, at the price of Three Dollars and
75/100 ($3.75) per Share (as defined in Section 3) at any time, or in part from
time to time in accordance with the following Vesting Schedule ("Vesting
Schedule"):

           Date:                                Total Shares Subject to Exercise

From and after January 30, 2002                               16,667
From and after January 30, 2003                               33,334
From and after January 30, 2004                               50,000

This Warrant shall expire, if not exercised prior thereto, two (2) years after
the resignation or removal of Obourn as an employee of the Company.  If Obourn
should resign or be removed as an employee from the Company, then this Warrant
shall be vested only to the extent vested on such date of resignation or removal
according to the Vesting Schedule.  The provisions as to adjustment of the
initial exercise price set forth above and the number of Shares to be issued
upon the occurrence of certain events (the Provisions as to Adjustment) are more
fully set forth in Annex 1 hereto.  (Hereinafter, the initial exercise price set
forth above in this paragraph for the purchase of Shares upon the exercise of
this Warrant, as adjusted pursuant to the Provisions as to Adjustment, is
referred to as the "Exercise Price").  This Warrant is subject to the following
provision, terms and conditions:

     1.  Exercise of Warrant.
         -------------------

     (a) The rights represented by this Warrant may be exercised by the holder
hereof, in whole or in part, (but not as to a fractional Share), by the
surrender of this Warrant at the Company's principal office located in Denver,
Colorado (or such other office or agency of the Company as the Company may
designate by notice in writing to the holder hereof at the address of such
holder appearing on the books of the Company at any time within the period above
named) and delivery of a completed subscription form in the form attached to
this Warrant as Exhibit A, and upon payment to the Company of the Exercise Price
                ---------
for such Shares.
<PAGE>

     (b) Payment of the Exercise Price shall be made by a combination of any one
or more of the following:

         (i)  By application, to the extent permitted by applicable law, of
              Shares or other securities of the Company owned by the holder
              hereof, the value of which for such purpose shall be the fair
              market value thereof determined in good faith by the Company and
              the holder hereof at the time of such exercise; provided,
              however, that in order to apply such Shares or other securities
              of the Company in the exercise hereof, each of the following
              conditions must be met:

              (A)  Such Shares or other securities of the Company shall have
                   been owned, without material encumbrance, contingency or
                   risk of forfeiture relating to the ownership rights, for at
                   least six months and at all times during said six month
                   period by the holder hereof, and within said six month
                   period such Shares or other securities of the Company shall
                   not have been obtained through exercise of any option,
                   warrant or right to obtain such Shares of other securities
                   or through the conversion of any other security; and

              (B)  Such Shares or other securities shall not be or include: (1)
                   options, warrants or similar rights to acquire Shares or
                   other securities of the Company by the holder hereof; or (2)
                   securities owned by the holder hereof which are convertible
                   in whole or in part into Shares or other securities of the
                   Company.

         (ii) in cash or by certified check or bank draft in New York Clearing
              House funds.

     (c) The Company agrees that any Shares so purchased by the exercise of this
Warrant shall be deemed to be issued to the holder hereof as the record owner of
such Shares as of the close of business on the date on which this Warrant shall
have been surrendered, the completed subscription form delivered, and payment in
full is made and delivered to the Company for such Shares as aforesaid.

     (d) Stock certificates evidencing Shares so purchased shall be delivered to
the holder hereof as promptly as practicable, after the rights represented by
this Warrant shall have been so exercised.  If this Warrant shall have been
exercised only in part, and unless this Warrant has expired, a new Warrant
representing the number of Shares with respect to which this Warrant shall not
then have been exercised shall also be delivered to the holder hereof within
such time.  Notwithstanding the foregoing, however, the Company shall not be
required to deliver any stock certificate evidencing Shares upon exercise of
this Warrant except in accordance with the provisions, and subject to the
limitations, of Section 5.  The Company will pay all expenses and charges
payable
<PAGE>

in connection with the preparation, execution and delivery of stock certificates
and any new Warrants or promissory notes.

     2.  Certain Covenants of the Company.  The Company covenants and agrees as
         --------------------------------
follows:

     (a) All Shares which may be issued upon the exercise of the rights
represented by this Warrant (all such Shares, whether previously issued or
subject to issuance upon the exercise of this Warrant, are from time to time
referred to herein as "Warrant Shares") will, upon issuance, be duly authorized
and issued, fully paid and nonassessable and free from all taxes, liens and
charges with respect to the issuance thereof.

     (b) During the period within which the rights represented by this Warrant
may be exercised, and only insofar as the Vesting Schedule herein permits the
exercise of this Warrant, the Company will at all times have authorized and
reserved free of preemptive or other rights for the exclusive purpose of
issuance upon exercise of the purchase rights evidenced by this Warrant, a
sufficient number of Shares to provide for the exercise of rights represented by
this Warrant.

     (c) The Company will not, by amendment or restatement of the Articles of
Incorporation or through any reorganization, transfer of assets, consolidation,
merger, issuance or sale of securities or otherwise, avoid or take any action
which would have the effect of avoiding the performance of any of the terms to
be performed hereunder by the Company, but will at all times in good faith carry
out all of the provisions of this Warrant and take all such action as may be
necessary or appropriate to protect the rights of the holder hereof against
dilution or other impairment and, in particular, will not permit the par value
of any Share to be or become greater than the then effective Exercise Price.

     3.  Definition of Shares.  As used herein, the term "Shares" shall mean and
         --------------------
include shares of the Common Stock, par value $.02 per share, of the Company as
are constituted and exist on the date hereof, and shall also include any other
class of the capital stock of the Company hereafter authorized which shall
neither be limited to a fixed sum or percentage of par value in respect to the
rights of the holders thereof to receive dividends and to participate in the
distribution of assets upon the voluntary or involuntary liquidation,
dissolution or winding up of the Company, nor be subject at any time to
redemption by the Company; provided that the Shares receivable upon exercise of
this Warrant shall include only Shares of the type as are constituted and exist
on the date hereof or Shares resulting from any reclassification of the Shares
as provided for in paragraph (C) of the Provisions as to Adjustment.

     4.  No Rights or Liabilities as a Shareholder.  This Warrant shall not
         -----------------------------------------
entitle the holder hereof as such to any rights whatsoever, including, without
limitation, voting rights, as a holder of Shares of the Company.  No provisions
hereof, in the absence of affirmative action by the holder hereof to purchase
Shares, and no mere enumeration herein of the rights or privileges of such
holder,

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shall give rise to any liability of such holder as a holder of Shares of the
Company, regardless of who may assert such liability.

     5.  Restrictions on Transfer.
         ------------------------

     (a) This Warrant shall not be exercisable by a transferee hereof and/or
transferable and the Warrant Shares shall not be transferable except upon the
conditions specified in this Section 5, which conditions are intended, among
other things, to ensure compliance with the provisions of the Securities Act of
1933, as amended, and the rules and regulations of the Securities and Exchange
Commission (the "Commission") thereunder (collectively the "Securities Act"), in
respect of the exercise and/or transfer of this Warrant and/or transfer of such
Warrant Shares.

     (b) This Warrant and the Warrant Shares shall not be transferable (except
for a transfer of this Warrant or the Warrant Shares in an offering registered
under the Securities Act, including, without limitation, a transfer in a
registered offering effected pursuant to Section 6, and any subsequent transfer)
unless, prior to any transfer, the holder hereof shall have received from its
transferee reasonable assurances that such person is aware that this Warrant and
the Warrant Shares have not been registered under the Securities Act and that
such person is acquiring this Warrant or the Warrant Shares for investment only
and not with the view to the disposition or public offering thereof (unless in
an offering registered under the Securities Act of 1933 or exempt therefrom),
and that such person is aware that the stock certificates evidencing the Warrant
Shares shall bear a legend restricting transfer and disposition thereof in
accordance with the Securities Act unless, in the opinion of counsel to the
Company, such legend may be omitted.  In the event of any transfer of this
Warrant (other than a transfer in an offering registered under the Securities
Act, including, without limitation, a transfer in a registered offering effected
pursuant to Section 6, and any subsequent transfer), the holder hereof shall
provide an opinion of counsel, who shall be reasonably satisfactory to the
Company, that an exemption from the registration requirements of the Securities
Act is available.

     (c) Any permitted subsequent holder of this Warrant shall be subject to all
the terms and conditions herein, and shall acknowledge, in writing, upon receipt
of this Warrant his or her acceptance of the terms and conditions herein.

     (d) To facilitate sales by a holder of this Warrant or Warrant Shares in
transactions qualifying under Rule 144 promulgated by the Commission under the
Securities Act, if available, the Company agrees to satisfy the current public
information requirements of said Rule 144, for as long as the Shares remain
registered under the Securities Exchange Act of 1934, as amended, and the rules
and regulations of the Commission thereunder (collectively the "Exchange Act"),
and to provide said holder upon request with such other information as such
holder may require for compliance with the provisions of said Rule 144.

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     6.  Registration Under Securities Act.
         ---------------------------------

     (a) If the Company at any time proposes to register any issuance of its
securities under the Securities Act (other than a registration on Form S-8 in
connection with an employee stock purchase or option plan or on Form S-4 in
connection with mergers, acquisitions or exchange offerings), the Company will
at such time give prompt written notice to the holder hereof and to the holders
of all other Warrant Shares issuable from any outstanding Warrants (such holders
are hereinafter referred to as the "Prospective Sellers") of its intention to do
so.  Upon the written request of a Prospective Seller, given within 30 days
after receipt of any such notice (which request shall state the intended method
of disposition of the Warrant Shares to be transferred by such Prospective
Seller), the Company shall use its best efforts to cause all Warrant Shares, the
holders of which (or of the Warrants to which the same are related), to the
extent vested in accordance with the Vesting Schedule, shall have so requested
registration of the transfer thereof, to be registered under the Securities Act,
all to the extent requisite to permit the sale or other disposition (in
accordance with the intended method thereof as aforesaid) by the Prospective
Sellers of such Warrant Shares.  The rights granted pursuant to this Section
6(a) shall not be effective with respect to the Prospective Seller in the case
of an underwritten public offering of securities of the Company by the Company
unless each Prospective Seller agrees to the terms and conditions, including
underwriting discounts and allowances, specified by the managing underwriter of
such offering with respect to such Warrant Shares.  The Company shall have the
right to reduce the number of Warrant Shares of the Prospective Sellers to be
included in a registration statement pursuant to the exercise of the rights
granted by this Section 6(a) if, and to the extent, that the managing
underwriter of such offering is of the good faith opinion, supported by written
reasons therefor, that the inclusion of such Warrant Shares would materially
adversely affect the marketing of the securities of the Company to be offered;
provided, that any such reduction of the number of Warrant Shares the transfer
of which is to be registered on behalf of the Prospective Sellers shall be made
on the basis of a pro rata reduction of all Warrant Shares of all Prospective
Sellers.

     (b) If and whenever the Company is required by the provisions of this
Section 6 to use its best efforts to effect the registration of any transfer of
Warrant Shares under the Securities Act, the Company will, as expeditiously as
possible,

         (i)  prepare and file with the Commission a registration statement
              with respect to such transfer and use its best efforts to cause
              such registration statement to become and remain effective, but
              not for any period longer than nine months;

         (ii) prepare and file with the Commission such amendments and
              supplements to such registration statement and the prospectus
              used in connection therewith as may be necessary to keep such
              registration statement effective, and to comply with the
              provisions of the Securities Act with respect to the transfer

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                of all securities covered by such registration statement,
                including, without limitation, taking all necessary actions
                whenever the Prospective Sellers of the Warrant Shares covered
                by such registration statement shall desire to dispose of the
                same;

         (iii)  furnish to each Prospective Seller such number of copies of a
                prospectus, including a preliminary prospectus, in conformity
                with the requirements of the Securities Act, and such other
                documents, as such Prospective Seller may reasonably request in
                order to facilitate the disposition of the Warrant Shares owned
                by such Prospective Seller and covered by such registration
                statement;

         (iv)   use its best efforts to register or qualify the securities
                covered by such registration statement under such other
                securities or blue sky laws of such jurisdictions as each
                Prospective Seller shall request, and use its best efforts to do
                any and all other acts and things which may be reasonably
                necessary to enable such Prospective Seller to consummate the
                disposition in such jurisdiction of the Warrant Shares owned by
                such Prospective Seller and covered by such registration
                statement; provided that, notwithstanding the foregoing, the
                Company shall not be required to register in any jurisdiction as
                a broker or dealer of securities or to grant its consent to
                service of process in any such jurisdiction solely on account of
                such intended disposition by such Prospective Seller;

         (v)    furnish to the Prospective Sellers whose intended dispositions
                are registered a signed copy of an opinion of counsel for the
                Company, in form and substance acceptable to such Prospective
                Sellers, to the effect that: (A) a registration statement
                covering such dispositions of Warrant Shares has been filed with
                the Commission under the Securities Act and has been made
                effective by order of the Commission, (B) such registration
                statement and the prospectus contained therein and any
                amendments or supplements thereto comply as to form in all
                material respects with the requirements of the Securities Act,
                and nothing has come to such counsel's attention which would
                cause him to believe that the registration statement or such
                prospectus, amendment or supplement, at the time such
                registration statement or amendment became effective or such
                supplement was filed with the Commission, contained any untrue
                statement of a material fact or omitted to state a material fact
                required to be stated therein or necessary to make the
                statements therein (in the case of such prospectus, amendment or
                supplement, in the light of the circumstances under which they
                were made) not misleading (provided that such counsel need not
                render any opinion with respect to the financial statements and
                other financial, engineering and statistical data

Page 6 - Warrant to Purchase Shares
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                included therein), and (C) to the best of such counsel's
                knowledge, no stop order has been issued by the Commission
                suspending the effectiveness of such registration statement and
                no proceedings for the issuance of such a stop order are
                threatened or contemplated;

         (vi)   furnish to the Prospective Sellers whose intended dispositions
                are required a blue sky survey in the form and of the substance
                customarily prepared by counsel for the Company and accepted by
                sellers of securities in similar offerings, discussing and
                describing the application provisions of the securities or blue
                sky laws of each state or jurisdiction in which the Company
                shall be required, pursuant to Section 6(c)(iv), to register or
                qualify such intended dispositions of such Warrant Shares, or,
                in the event counsel for the underwriters in such offering shall
                be preparing a blue sky survey, cause such counsel to furnish
                such survey to, and to allow reliance thereon by, such
                Prospective Sellers;

         (vii)  otherwise use its best efforts to comply with all applicable
                rules and regulations of the Commission under the Securities Act
                and the Exchange Act, insofar as they relate to such
                registration and such registration statement; and

         (viii) use its best efforts to list such Warrant Shares on any
                securities exchange on which any securities of the Company are
                then listed or to admit such Warrant Shares for trading in any
                national market system in which any securities of the Company
                are then admitted for trading, if the listing or admission of
                such securities is then permitted under the rules of such
                exchange or system.

     (c) With respect to the registration by the Company of transfers of Warrant
Shares under the Securities Act pursuant to Section 6(a), the Company shall pay
all expenses incurred by it in complying with this Section 6 (including, without
limitation, all registration and filing fees, printing expenses, blue sky fees
and expenses, costs and expenses of audits, and reasonable fees and
disbursements of counsel for the Company and special counsel designated by
Prospective Sellers owning a majority of the Warrant Shares covered by such
registration, but specifically excluding any underwriting discounts and
allowances that are allocable to the Warrant Shares being sold by, and which
shall be paid by, the Prospective Sellers; provided, however, that if any
registration statement filed with the Commission by the Company under Section
6(a) shall not be declared effective by the Commission, such attempted
registration shall not constitute a registration under this Section 6(c).

     (d) It shall be a condition precedent to the obligations of the Company to
take any action pursuant to this Section 6 that each Prospective Seller, the
transfer of whose Warrant Shares is registered or to be registered under each
such registration, shall furnish to the Company such written

Page 7 - Warrant to Purchase Shares
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information regarding the securities held by such Prospective Seller as the
Company shall reasonably request and as shall be required in connection with the
action to be taken by the Company.

     (e) (i)  In the event of any registration of any transfer of Warrant
Shares under the Securities Act pursuant to this Section 6, the Company will
indemnify and hold harmless each Prospective Seller of such securities, each of
its officers, directors and partners, and each other person, if any, who
controls such Prospective Seller within the meaning of the Securities Act, and
each underwriter, if any, who participates in the offering of such securities,
against any losses, claims, damages or liabilities (or actions in respect
thereof), joint or several, to which each Prospective Seller, officer, director
or partner, controlling person or underwriter may become subject under the
Securities Act or otherwise, insofar as such losses, claims, damages or
liabilities (or actions in respect thereof) arise out of or are based upon any
untrue statement or alleged untrue statement of any material fact contained, on
the effective date thereof, in any registration statement under which such
transfer of securities was registered under the Securities Act, any preliminary
prospectus or final prospectus contained therein, or any amendment or supplement
thereto, or arise out of or are based upon the omission or alleged omission to
state therein a material fact required to be stated therein or necessary to make
the statements therein not misleading, or any violation by the Company of the
Securities Act, and will reimburse such Prospective Seller and each of its
officers, directors and partners, and each such controlling person or
underwriter, for any legal or any other expenses reasonably incurred by such
Prospective Seller or its officers, directors and partners or controlling
persons or by each such underwriter, in connection with investigating or
defending any such loss, claim, damage, liability or action; provided, however,
that the Company will not be liable in any such case to the extent that any such
loss, claim, damage or liability arises out of or is based upon an untrue
statement or alleged untrue statement or omission or alleged omission made in
such registration statement, preliminary prospectus or prospectus or such
amendment or supplement in reliance upon and in conformity with written
information furnished to the Company through an instrument duly executed by such
Prospective Seller specifically for use in the preparation thereof.  In the
event of any registration by the Company or any transfer of securities under the
Securities Act pursuant to this Section 6, each Prospective Seller of Warrant
Shares covered by such registration will indemnify and hold harmless the
Company, each other person, if any, who controls the Company within the meaning
of the Securities Act and each officer and director of the Company and the other
Prospective Sellers to the same extent that the Company agrees to indemnify it,
but only with respect to the written information relating to such Prospective
Seller furnished to the Company by such Prospective Seller aforesaid.

         (ii) Each indemnified party shall, as promptly as practicable upon
receipt of notice of the commencement of any action against such indemnified
party or its officers, directors or partners, or any controlling person of such
indemnified party, in respect of which indemnity may be sought from an
indemnifying party on account of the indemnity agreement contained in Section
6(e)(i), notify the indemnifying party in writing of the commencement thereof.
The omission of such indemnified party to so notify the indemnifying party of
any such action shall not relieve the

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<PAGE>

indemnifying party from any liability which it may have on account of the
indemnity agreement contained in Section 6(e)(i) to the extent that the failure
to receive such notice within a reasonable period of time shall not have caused
harm, loss or damage to the indemnifying party, provided that, conversely, if
such failure to receive notice shall have caused any harm, loss or damage to the
indemnifying party, such failure shall constitute a defense to any liability
which such indemnifying party may have on account of such agreement to the
extent of the harm, loss or damage so caused. In case any such action shall be
brought against any indemnified party, its officers, directors and partners, or
any such controlling person, and such indemnified party shall notify the
indemnifying party of the commencement thereof, the indemnifying party shall be
entitled to participate in (and, to the extent that the indemnifying party shall
wish, to direct) the defense thereof at the indemnifying party's own expense, in
which event the defense shall be conducted by recognized counsel chosen by the
indemnifying party and approved by the indemnified party (whose approval shall
not unreasonably be withheld) and the indemnified party may participate in such
defense at its own expense (unless it is advised by counsel that actual or
potential differing interests or defenses exist or may exist, in which case such
expenses shall be paid by the indemnifying party, provided that the indemnifying
party shall not be required to pay the expenses for more than one counsel for
all such indemnified parties).

     7.  Transfer; Ownership.  Subject to Section 5, this Warrant and all rights
         -------------------
hereunder are transferable, in whole or in part, at the office or agency of the
Company referred to in Section 1 by the holder hereof in person or by a duly
authorized attorney, upon surrender of this Warrant, with an assignment,
acceptable to the Company, duly completed, at which time a new Warrant shall be
made and delivered by the Company, of the same tenor as this Warrant but
registered in the name of the transferee.  The holder of this Warrant, by taking
or holding the same, consents and agrees that this Warrant, when endorsed in
blank, shall be deemed negotiable, and that the holder hereof, when this Warrant
shall have been so endorsed, may be treated by the Company and all other persons
dealing with this Warrant as the absolute owner hereof for any purpose and as
the person entitled to exercise the rights represented by this Warrant and to
transfer this Warrant on the books of the Company, any notice to the contrary
notwithstanding; but until such transfer on such books, the Company may treat
the registered holder hereof as the owner hereof for all purposes.  Any transfer
of this Warrant shall be made in compliance with the Securities Act and any
applicable statute securities or blue sky laws.

     8.  Exchange and Replacement.  Subject to Section 7, this Warrant is
         ------------------------
exchangeable, upon the surrender hereof by the holder hereof at the office or
agency of the Company referred to in Section 1, for new Warrants of like tenor
and date representing in the aggregate the right to purchase the number of
Shares which may be purchased hereunder, each of such new Warrants to represent
the right to purchase such number of Shares as shall be designated by said
holder hereof at the time of such surrender.  Upon receipt by the Company at the
office or agency referred to in Section 1 of evidence reasonably satisfactory to
it of the loss, theft or destruction of this Warrant and of indemnity or
security reasonably satisfactory to it (provided that the written indemnity of
the

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<PAGE>

holder hereof shall be deemed reasonably satisfactory to the Company for such
purposes), the Company will deliver a new Warrant of like tenor and date in
replacement of this Warrant. This Warrant shall be promptly canceled by the
Company upon the surrender hereof in connection with any transfer, exchange or
replacement. The Company will pay all expenses and charges payable in connection
with the preparation, execution and delivery of Warrants pursuant to Section 7
and this Section 8.

     9.  Notices.  Any notice or other document required or permitted to be
         -------
given or delivered to the holder hereof shall be delivered at, or sent by
certified or registered mail to, 5585 Cherryville Way, Greenwood Village,
Colorado 80121, or to such other address as shall have been furnished to the
Company in writing by the holder hereof.  Any notice or other document required
or permitted to be given or delivered to the Company shall be delivered at, or
sent by certified or registered mail to, 633 Seventeenth Street, Suite 1550,
Denver, Colorado 80202, or to such other address as shall have been furnished in
writing to the holder hereof by the Company.  Any notice so addressed and mailed
by registered or certified mail or otherwise delivered, shall be deemed to be
given when actually received by the addressee.

     10. GOVERNING LAW.  THIS WARRANT SHALL BE GOVERNED BY, AND CONSTRUED AND
         -------------
ENFORCED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF TEXAS.

     11. Miscellaneous.  This Warrant will be binding upon any entity
         -------------
succeeding to the Company by consolidation or acquisition of all or
substantially all of the Company's assets, and upon any successor or assign of
the holder hereto.  This Warrant and any provision hereof may be changed,
waived, discharged or terminated only by an instrument in writing signed by the
party (or any predecessor in interest thereof) against whom enforcement of the
same is sought.  The headings in this Warrant are for purposes of reference only
and shall not affect the meaning or construction of any of the provisions
hereon.

     IN WITNESS WHEREOF, Tipperary Corporation has caused this Warrant to be
signed by its duly authorized officers, under its corporate seal, to be dated
January 30, 2001.

                                         TIPPERARY CORPORATION

                                         BY: /s/ David L. Bradshaw
                                            ----------------------
                                          ITS: President
                                              --------------------

(CORPORATE SEAL)

ATTEST:   /s/ Elaine R. Treece
          --------------------
   ITS:   Secretary

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<PAGE>

                                                                         Annex 1

                             TIPPERARY CORPORATION

                         PROVISIONS AS TO ADJUSTMENT OF
                      EXERCISE PRICE AND NUMBER OF SHARES
                    ISSUED UPON OCCURRENCE OF CERTAIN EVENTS
                    ----------------------------------------

     The Exercise Price and the number of Shares issuable upon the exercise of
the annexed Warrant to purchase shares of TIPPERARY CORPORATION, a Texas
corporation (herein and in this Warrant referred to as the "Company"), shall be
subject to adjustment from time to time as hereinafter provided; that in no
event shall the Exercise Price be increased to a price greater than Three
Dollars and 75/100 ($3.75) per Share, except as provided by paragraph (C).  Upon
each adjustment of the Exercise Price, the holder of this Warrant shall
thereafter be entitled to purchase, at the Exercise Price resulting from such
adjustment, the number of Shares obtained by multiplying the number of Shares
purchasable pursuant hereto immediately prior to such adjustment by a fraction,
the numerator of which is the Exercise Price in effect immediately prior to such
adjustment and the denominator of which is the Exercise Price resulting from
such adjustment.  In making the adjustments to the Exercise Price and the number
of Shares issuable upon the exercise of this Warrant, the following provisions
shall be applicable:

     (A) If and whenever the Company shall issue or sell any Shares for
consideration per Share that is less than the Exercise Price in effect
immediately prior to the time of such issue or sale at less than the Market
Price (as hereinafter defined) of such Shares on the date of such issue or sale,
then forthwith upon such issue or sale the Exercise Price in effect immediately
prior thereto shall be adjusted to an amount (calculated to the nearest cent)
determined by dividing (i) an amount equal to the sum of (a) the number of
Shares outstanding immediately prior to such issue or sale multiplied by the
Exercise Price in effect immediately prior to such issue or sale, and (b) the
consideration, if any, received by the Company upon such issue or sale by (ii)
the total number of Shares outstanding immediately after such issue or sale;
provided, however, that no adjustment shall be made hereunder by reason of:

         (i)   the grant of this Warrant or the issuance of Shares upon the
               exercise of this Warrant or any other outstanding Warrant;

         (ii)  the grant by the Company of options to purchase shares in
               connection with any purchase or option plan for the benefit of
               employees of the Company, or any affiliates or subsidiaries
               thereof; or

         (iii) the issuance (whether directly or by assumption in a merger or
               otherwise) or sale (including any issuance or sale to holders of
               Shares) of any securities convertible into or exchangeable for
               Shares (such convertible or exchangeable
<PAGE>

               securities are herein referred to as "Convertible Securities"),
               or the grant of rights to subscribe for or to purchase, or of
               options for the purchase of (including any grant of such rights
               or options to holders of shares, other than pursuant to a
               dividend on Shares), Shares of Convertible Securities, regardless
               of whether the right to convert or exchange such Convertible
               Securities or such rights or options are immediately exercisable.

No adjustment of the Exercise Price shall be required to be made by the Company
and no notice hereunder must be given if the amount of any required adjustment
is less than 5% of the Exercise Price.  In such case any such adjustment shall
be carried forward and shall be made (and notice thereof shall be given
hereunder) at the time of and together with the next subsequent adjustment
which, together with any adjustment so carried forward, shall amount to not less
than 5% of the Exercise Price.

     (B) For the purposes of paragraph (A), the following provisions (i) through
(vi), inclusive, shall also be applicable:

         (i)  If, at the time Shares are issued and sold upon the conversion or
              exchange of Convertible Securities or upon the exercise of rights
              or options previously granted by the Company, the price per Share
              for which such Shares are issued (determined by dividing (a) the
              total amount, if any, received by the Company as consideration for
              such Convertible Securities or for the granting of such rights or
              options, plus the aggregate amount of additional consideration
              paid to the Company upon the conversion or exchange of such
              Convertible Securities (which, if so provided in such Convertible
              Securities, shall be deemed to be equal to the outstanding
              principal amount of the indebtedness represented by such
              Convertible Securities) or upon the exercise of such rights or
              options, by (b) the total number of Shares issued upon the
              conversion or exchange of such Convertible Securities or upon the
              exercise of such rights or options) shall be less than the
              Exercise Price in effect immediately prior to such issue, sale or
              exercise, then the adjustments provided for by the first paragraph
              of this Annex 1 and paragraph (A) shall be made.  In making the
              adjustment of the Exercise Price provided for by paragraph (A),
              the amount described in clause (a) of this paragraph (B)(i) shall
              be considered the consideration received by the Company upon the
              issue or sale of the Shares for purposes of clause (i)(b) of
              paragraph (A).

         (ii) In case at any time any Shares or Convertible Securities or any
              rights or options to purchase any Shares or Convertible Securities
              shall be issued or sold for cash, the consideration received
              therefor shall be deemed to be the amount received by the Company
              therefor without deduction therefrom of any expenses

Page 2 - Annex 1
<PAGE>

                incurred or any underwriting commissions or concessions paid or
                allowed by the Company in connection therewith. In case any
                Shares or Convertible Securities or any rights or options to
                purchase any Shares or Convertible Securities shall be issued or
                sold, in whole or in part, for consideration other than cash,
                the amount of the consideration other than cash received by the
                Company in exchange for the issue or sale of such Convertible
                Securities shall be deemed to be the fair value of such
                consideration as determined in good faith by the Board of
                Directors of the Company, without deduction therefrom of any
                expenses incurred or any underwriting commissions or concessions
                paid or allowed by the Company in connection therewith; provided
                that if the holder or holders of at least 66-2/3% of the Warrant
                Shares purchasable under this Warrant shall request in writing,
                the value of such consideration shall be determined by an
                independent expert selected by such holders, the costs and
                expenses of which shall be borne by the Company, and, if the
                value of such consideration as so determined is less than the
                value determined by the Board of Directors of the Company, the
                lesser value shall be utilized in calculating the consideration
                per Share received by the Company for purposes of making the
                adjustment provided by paragraph (A). In the event of any merger
                or consolidation of the Company in which the Company is not the
                surviving corporation or in the event of any sale of all or
                substantially all of the assets of the Company for stock or
                other securities of any corporation, the Company shall be deemed
                to have issued a number of Shares for stock or securities of
                such other corporation computed on the basis of the actual
                exchange ratio on which the transaction was predicated and for
                consideration that is equal to the fair market value on the date
                of such transaction of such stock or securities of the other
                corporation, and if any such calculation results in adjustment
                of the Exercise Price, the determination of the number of Shares
                issuable upon exercise of this Warrant immediately prior to such
                merger, consolidation or sale, for purposes of paragraph (A),
                shall be made after giving effect to such adjustment of the
                Exercise Price.

         (iii)  The number of Shares outstanding at any given time shall not
                include Shares that have been redeemed by the Company and not
                canceled, if any, and that are thus owned or held by or for the
                account of the Company, and the disposition of any such Shares
                shall be considered an issue or sale of Shares for purposes of
                paragraph (A).

         (iv)   "Market Price" shall mean the lower of (a) the average closing
                sales prices of Shares recorded on the principal national
                securities exchange on which the Shares are listed or in a
                national market system for securities in which the Shares are
                admitted to trading or (b) the average of the closing bid and
                asked

Page 3 - Annex 1
<PAGE>

                prices of Shares reported in the domestic over-the-counter
                market, for the 20 trading days immediately prior to the day as
                of which the Market Price is being determined. If the Shares are
                not listed on any national securities exchange or admitted for
                trading in any national market system or traded in the domestic
                over-the-counter market, the Market Price shall be the higher of
                (y) the book value of the Shares as determined by a firm of
                independent public accountants of recognized standing selected
                by the Board of Directors of the Company as of the last day of
                any month ending within 60 days preceding the date as of which
                the determination is to be made or (z) the fair market value of
                the Shares determined in good faith by the Board of Directors of
                the Company, provided that if the holder or holders of at least
                66-2/3% of the Warrant Shares purchasable under the Warrant
                shall request in writing, the fair market value of the Shares
                shall be determined by an independent investment banking firm or
                other independent expert selected by such holders and reasonably
                satisfactory to the Company, which determination shall be as of
                a date which is within 15 days of the date as of which the
                determination is to be made.

         (v)    Anything herein to the contrary notwithstanding, in case the
                Company shall issue any Shares in connection with the
                acquisition by the Company of the stock or assets of any other
                corporation or the merger of any other corporation into the
                Company under circumstances where, on the date of the issuance
                of such Shares, the consideration received for such Shares is
                less than the Market Price of the Shares, but on the date the
                number of Shares was determined, the consideration received for
                such Shares would not have been less than the Market Price
                thereof, such Shares shall not be deemed to have been issued for
                less than the Market Price.

         (vi)   Anything in clause (ii) of this paragraph (B) to the contrary
                notwithstanding, in the case of an acquisition where all or part
                of the purchase price is payable in Shares or Convertible
                Securities but is stated as a dollar amount, where the Company
                upon making the acquisition pays only part of a maximum dollar
                purchase price which is payable in Shares or Convertible
                Securities and where the balance of such purchase price is
                deferred or is contingently payable under a formula related to
                earnings over a period of time, (a) the consideration received
                for any Shares or Convertible Securities delivered at the time
                of the acquisition shall be deemed to be such part of the total
                consideration as the portion of the dollar purchase price then
                paid in Shares or Convertible Securities bears to the total
                maximum dollar purchase price payable in Shares or Convertible
                Securities and (b) in connection with each issuance of
                additional Shares or Convertible Securities pursuant to the
                terms of the agreement relating to such acquisition, the
                consideration received shall be deemed to be such part

Page 4 - Annex 1
<PAGE>

                of the total consideration as the portion of the dollar purchase
                price then and theretofore paid in Shares or Convertible Shares
                bears to the total maximum dollar purchase price payable in
                Shares or Convertible Securities multiplied by a fraction, the
                numerator of which shall be the number of Shares (or in the case
                of Convertible Securities other than capital stock of the
                Company, the aggregate principal amount of such Convertible
                Securities) then issued and the denominator of which shall be
                the total number of shares (or in the case of Convertible
                Securities other than capital stock of the Company, the
                aggregate principal amount of such Convertible Securities) then
                and theretofore issued under such acquisition agreement. In the
                event only a part of the purchase price for an acquisition is
                paid in Shares or Convertible Securities in the manner referred
                to in this clause (vi), the term "total consideration" as used
                in this clause (vi) shall mean that part of the aggregate
                consideration as is fairly allocable to the purchase price paid
                in Shares or Convertible Securities in the manner referred to in
                this clause (vi), as determined by the Board of Directors of the
                Company.

     (C) In the case at any time the Company shall subdivide its outstanding
Shares into a greater number of Shares, then from and after the record date for
such subdivision the Exercise Price in effect immediately prior to such
subdivision shall be proportionately reduced and the number of Shares
purchasable upon the exercise of this Warrant shall be correspondingly
increased, and, conversely, in case the outstanding Shares shall be combined
into a smaller number of Shares, then from and after the record date for such
combination the Exercise Price in effect immediately prior to such combination
shall be proportionately increased and the number of Shares purchasable upon the
exercise of this Warrant shall be correspondingly decreased.

     (D) Unless the provisions of paragraph (E) apply, if any capital
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, shall be effected in
such a way that holders of Shares (or any other securities of the Company then
issuable upon the exercise of this Warrant) shall be entitled to receive stock,
securities or assets with respect to or exchange for Shares (or such other
securities) then, as a condition of such reorganization, reclassification,
consolidation, merger or sale, lawful and adequate provision shall be made
whereby the holder hereof shall thereafter have the right to purchase and
receive upon the basis and upon the terms and conditions specified in this
Warrant and in lieu of the Shares (or other securities) of the Company
immediately theretofore purchasable and receivable upon the exercise of the
rights represented hereby, such shares of stock, securities or assets as may be
issued or payable with respect to or in exchange for a number of outstanding
Shares (or other securities) equal to the number of Shares (or other securities)
immediately theretofore so purchasable and receivable 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 the holder of this

Page 5 - Annex 1
<PAGE>

Warrant to the end that the provisions hereof (including, without limitation,
provisions for adjustment of the Exercise Price and of the number of Shares (or
other securities) purchasable upon the exercise of this Warrant and for the
registration thereof as provided in Section 6 of this Warrant) shall thereafter
be applicable, as nearly as may be, in relation to any shares of stock,
securities or assets thereafter deliverable upon the exercise hereof (including
an immediate adjustment, by reason of such consolidation, merger or sale, of the
Exercise Price to the value of the Shares (or other securities) reflected by the
terms of such consolidation, merger or sale if the value so reflected is less
than the Exercise Price in effect immediately prior to such consolidation,
merger or sale). In the event of a consolidation or merger of the Company with
or into another corporation as a result of which a greater or lesser number of
securities of the surviving corporation are issuable to holders of Shares in
respect of the number of Shares outstanding immediately prior to such
consolidation or merger, then the Exercise Price in effect immediately prior to
such consolidation or merger shall be adjusted in the same manner as though
there were a subdivision or combination of the outstanding Shares. The Company
shall not effect any such consolidation, merger or sale, unless prior to or
simultaneously with the consummation thereof the surviving or successor
corporation (if other than the Company) resulting from such consolidation or
merger of the corporation purchasing such assets shall assume, by written
instrument executed and mailed to the registered holder hereof at the last
address of such holder appearing on the books of the Company, the obligation to
deliver to such holder such Shares of stock, securities or assets as, in
accordance with the foregoing provisions, such holder may be entitled to
purchase, and containing the express assumption of such surviving or successor
corporation of the due performance of every provision of this Warrant to be
performed by the Company and of all liabilities and obligations of the Company
hereunder.

     (E) In the event of a change in control of the Company, as defined in this
paragraph (E), then the Board of Directors shall accelerate the exercise date of
the Warrant or make this Warrant fully vested and exercisable and, in its sole
discretion, may take any or all of the following actions: (a) grant a cash bonus
award to any holder of this Warrant in an amount necessary to pay the Exercise
Price of all or any portion of the Warrant then held by such person; (b) pay
cash to any holder of this Warrant in exchange for the cancellation of the
holder's Warrant in an amount equal to the difference between the Exercise Price
of such Warrant and the greater of the tender offer price for the underlying
Shares or the Market Price of the Shares on the date of the cancellation of the
Warrant; and (c) make any other adjustments or amendments to this Warrant.  For
purposes of this paragraph (E), a "change in control" shall be deemed to have
occurred if (a) any "person" or "group" (within the meaning of Sections 13(d)
and 14(d)(2) of the Securities Exchange Act of 1934, as amended ("1934 Act"),
other than a trustee or other fiduciary holding securities under an employee
benefit plan of the Company is or becomes the "beneficial owner" (as defined in
Rule 13d-3 under the 1934 Act), directly or indirectly, of more than 50% of the
then outstanding voting stock of the Company; or (b) at any time during any
period of three consecutive years after the date of this Warrant, individuals
who at the beginning of such period constitute the Board (and any new director
whose election by the Board or whose nomination for election by the Company's
stockholders was approved by a vote of at least two-thirds of the directors then
still in office who either were directors

Page 6 - Annex 1
<PAGE>

at the beginning of such period or whose election or nomination for election was
previously so approved) cease for any reason to constitute a majority thereof;
or (c) the stockholders of the Company approve a merger or consolidation of the
Company with any other corporation, other than a merger or consolidation which
would result in the voting securities of the Company outstanding immediately
prior thereto continuing to represent (either by remaining outstanding or by
being converted into voting securities of the surviving entity) at least 50% of
the combined voting power of the voting securities of the Company or such
surviving entity outstanding immediately after such merger or consolidation.

     (F) In case at any time the Company shall pay any dividend on or make any
other distribution with respect to Shares (or any other securities of the
Company then issuable upon the exercise of the Warrant) that is payable in
Shares, Convertible Securities, any other securities of the Company or other
stock, securities or assets, other than cash, then thereafter, and in lieu of
any adjustment of the Exercise Price and the number of Shares issuable upon the
exercise of this Warrant, the holder of this Warrant, upon any exercise of the
rights represented hereby, shall be entitled to receive the number of Shares (or
other securities) being purchased upon such exercise and, in addition to and
without further payment, the Shares, Convertible Securities, other securities of
any company or other stock, securities or assets which the holder of this
Warrant would have received by way of such distributions if continuously since
the date of the Warrant (or, if this Warrant shall have been issued pursuant to
Section 7 of this Warrant, the date of the predecessor Warrant to which this
Warrant relates) such holder had been the record holder of the number of Shares
(or other securities), then being purchased and had retained all such Shares,
Convertible Securities, other securities of the Company or other stock,
securities or assets distributable with respect to such Shares (or other
securities) and, furthermore, all cash, stock, securities or assets payable as
dividends or distributions with respect to the foregoing and originating
directly or indirectly therefrom.  The Company shall reserve and retain in
escrow from any such dividend or distribution of Shares, Convertible Securities,
other securities of the Company or other stock, securities or assets, and from
any such dividends or distributions with respect thereto and originating
directly or indirectly therefrom, such Shares, Convertible Securities, other
securities of the Company and other stock, securities, assets and cash as shall
be necessary to fulfill its obligations to the holder hereof pursuant to this
paragraph (F).

     (G) If at any time conditions arise by reason of action taken by the
Company, which in the good faith opinion of the Board of Directors of the
Company, are not adequately covered by the provisions of this Annex 1, and which
might materially adversely affect the rights of the holder of this Warrant, the
Company shall appoint a firm of independent public accountants of recognized
standing (which may be the regular accountants or auditors of the Company),
which shall give their opinion as to the adjustments, if any, in the Exercise
Price and the number of Shares purchasable upon the exercise of this Warrant, or
other change in the rights of the holder hereof, on a basis consistent with the
other provisions of this Annex 1, necessary to preserve without diminution the

Page 7 - Annex 1
<PAGE>

rights of the holder hereof.  Upon receipt of such opinion, the Company shall
forthwith make the adjustments described therein.

     (H) (i)  Within ten (10) days of any adjustment of the Exercise Price or
              change in the number of Shares purchasable upon the exercise of
              this Warrant made pursuant to paragraphs (A), (B), (C) , or (F) or
              any change in the rights of the holder of this Warrant by reason
              of the occurrence of events described in paragraphs (D), (E), or
              (F), the Company shall give written notice by certified or
              registered mail to the registered holder of this Warrant at the
              address of such holder as shown on the books of the Company, which
              notice shall describe the event requiring such adjustments (with
              respect to any adjustment made pursuant to paragraphs (C), (D),
              (E) or (F), the Exercise Price resulting from such adjustment, the
              increase or decrease, if any, in the number of Shares purchasable
              upon the exercise of this Warrant, or the other change in the
              rights of such holder, and set forth in reasonable detail the
              method of calculation of such adjustments and the facts upon which
              such calculations are based.  Within two (2) days of receipt from
              the holder of this Warrant upon the surrender hereof for exercise
              pursuant to Section 1 of this Warrant, and within three (3) days
              of receipt from the holder hereof a written request therefor
              (which request shall not be made more than once each calendar
              quarter), the Company shall give written notice by certified or
              registered mail to such holder at his address as shown on the
              books of the Company of the Exercise Price in effect as of the
              date of receipt by the Company of this Warrant for exercise, or
              the date of receipt of such written request, and the number of
              Shares purchasable or the number or amount of other shares of
              stock, securities or assets receivable as of such date, and set
              forth in reasonable detail the method of calculation of such
              numbers; provided that no further adjustments to the Exercise
              Price or the number of Shares purchasable or number or amount of
              shares, securities or assets receivable on exercise of this
              Warrant shall be made after receipt of this Warrant by the Company
              for exercise.

         (ii) Upon each adjustment of the Exercise Price and each change in the
              number of Shares purchasable upon the exercise of this Warrant,
              and change in the rights of the holder of this Warrant by reason
              of the occurrence of other events herein set forth, then and in
              each case, upon written request of the holder of this Warrant
              (which request shall be made not more often than once each
              calendar year), the Company will at its expense promptly obtain an
              opinion of independent public accountants reasonably satisfactory
              to each holder stating the then effective Exercise Price and the
              number of Shares then purchasable, or specifying the other shares
              of stock, securities or assets and the amount thereof then
              receivable, and setting forth in reasonable detail the method of
              calculation of such numbers and the facts upon which such
              calculations are

Page 8 - Annex 1
<PAGE>

              based. The Company will promptly mail a copy of such opinion to
              the registered holder hereof.

     (I) In case at any time:

         (i)   The Company shall pay any dividend payable in capital stock on
               its outstanding Shares or make any distribution (other than
               regular cash dividends) to the holders of Shares;

         (ii)  The Company shall offer for subscription pro rata to the holders
               of Shares any additional capital stock or other rights;

         (iii) There shall be authorized any capital reorganization or
               reclassification of the capital stock of the Company, or
               consolidation or merger of the Company with, or sale of all or
               substantially all of its assets to, another corporation; or

         (iv)  There shall be authorized or commence a voluntary or involuntary
               dissolution, liquidation or winding up of the Company.

then, in one or more of said cases, the Company shall given written notice by
certified or registered mail to Obourn at the address of Obourn as shown on the
books of the Company on the date on which (1) the books of the Company shall
close or a record shall be taken for such dividend, distribution, or
subscription rights, or (2) such reorganization, reclassification,
consolidation, merger, sale, dissolution, liquidation or winding up shall take
place or be voted upon by the shareholders of the Company, as the case may be.
Such notice shall also specify the date as of which the holders of record of
Shares shall participate in such dividend, distribution or subscription rights,
or shall be entitled to exchange their Shares for securities or other property
deliverable upon such reorganization, reclassification, consolidation, merger,
sale, dissolution, liquidation or winding up, as the case may be.  Such written
notice shall be given at least thirty (30) days prior to the action in question
and no less than thirty (30) days prior to the record date or the date on which
the Company's books are closed in respect thereto.

Page 9 - Annex 1
<PAGE>

EXHIBIT A
---------

                               SUBSCRIPTION FORM

                    To be Executed by the Registered Holder
                  Desiring to Exercise the Within Warrant of
                             TIPPERARY CORPORATION

     The undersigned registered holder hereby exercises the right to purchase
__________________________ Shares covered by the within Warrant according to the
conditions thereof, and herewith makes payment of the Exercise Price of such
Shares, $ _____________________.

Name of Registered Holder:
                          ______________________________________________________

Signature:
          ______________________________________________________________________

Title of Signing Officer
or Agent (if any):
                  ______________________________________________________________

Address of Registered Holder:
                             ___________________________________________________

Tax I.D. No.:
             ___________________________________________________________________

Dated: ___________________________________, 20_______.Exhibit 4.3

                             CENTURY BANCORP, INC.

                             2000 STOCK OPTION PLAN

1.   PURPOSE

     The purpose of the Century Bancorp, Inc. 2000 Stock Option Plan is to
encourage ownership of Class A common stock of the Company by directors,
officers and employees of the Company and its Affiliates and to provide
additional incentives for them to promote the success of the Company's business
through the grant of options to purchase shares of the Company's Class A common
stock. The 2000 Stock Option Plan is intended to be an incentive stock option
plan within the meaning of Section 422 of the Code but not all Awards granted
hereunder are required to be Incentive Options.

2.   DEFINITIONS

     As used in this Plan the following terms shall have the respective
meanings set out below, unless the context clearly requires otherwise:

     2.1. Affiliate means any corporation, partnership, limited liability
company, business trust, or other entity controlling, controlled by or under
common control with the Company.

     2.2. Award means any grant of Options pursuant to the Plan.

     2.3. Board means the Company's Board of Directors.

     2.4. Class A Common Stock means Class A common stock, par value $1.00 per
share, of the Company.

     2.5. Code means the Internal Revenue Code of 1986, as amended from time to
time, or any statute successor thereto, and any regulations issued from time to
time thereunder.

     2.6. Company means Century Bancorp, Inc., a corporation organized under
the laws of the Commonwealth of Massachusetts.

     2.7. Compensation Committee means the Compensation Committee of the Board
or any other committee of the Board delegated by the Board responsibility for
the administration of the Plan, as provided in Section 5 of the Plan.

     2.8. Grant Date means the date as of which an Option is granted, as
determined under Section 7.1.

     2.9. Incentive Option means an Option which by its terms is to be treated
as an "incentive stock option" within the meaning of Section 422 of the Code.

<PAGE>

     2.10. Market Value means the value of a share of Class A Common Stock on
any date as determined by the Compensation Committee.

     2.11. Nonstatutory Option means any Option that is not an Incentive
Option.

     2.12. Option means an option to purchase shares of Class A Common Stock.

     2.13. Option Agreement means an agreement between the Company and the
recipient of an Award, setting forth the terms and conditions of the Award.

     2.14. Optionee means a Participant to whom an Award shall have been
granted under the Plan.

     2.15. Participant means any holder of an outstanding Option under the
Plan.

     2.16. Plan means this 2000 Stock Option Plan of the Company, as amended
from time to time.

     2.17. Ten Percent Owner means a person who owns, or is deemed within the
meaning of Section 422(b)(6) of the Code to own, stock possessing more than 10%
of the total combined voting power of all classes of stock of the Company (or
any Affiliate). Whether a person is a Ten Percent Owner shall be determined
with respect to each Option based on the facts existing immediately prior to
the Grant Date of such Option.

3.   TERM OF THE PLAN

     Unless the Plan shall have been earlier terminated by the Board, Options
may be granted hereunder at any time in the period commencing on the approval
of the Plan by the Board and ending immediately prior to the tenth anniversary
of the earlier of the adoption of the Plan by the Board or approval of the Plan
by the Company's Class B stockholders. Awards granted pursuant to the Plan
within such period shall not expire solely by reason of the termination of the
Plan. Awards of Incentive Options granted prior to approval of the Plan by the
Company's Class B stockholders are hereby expressly conditioned upon such
approval, but in the event of the failure of the Company's Class B stockholders
to approve the Plan shall thereafter and for all purposes be deemed to
constitute Nonstatutory Options.

4.   STOCK SUBJECT TO THE PLAN

     At no time shall the number of shares of Class A Common Stock issued
pursuant to or subject to outstanding Options granted under the Plan exceed
150,000 shares of Class A Common Stock; subject, however, to the provisions of
Section 8 of the Plan. For purposes of applying the foregoing limitation, if
any Option expires, terminates, or is cancelled for any reason without having
been exercised in full, the shares not purchased by the Optionee shall again be
available for Options thereafter to be granted under the Plan. Shares of Class
A Common Stock issued pursuant to the Plan may be either authorized but
unissued shares or shares held by the Company in its treasury.

<PAGE>

5.   ADMINISTRATION

     The Plan shall be administered by the Compensation Committee. Subject to
the provisions of the Plan, the Compensation Committee shall have complete
authority, in its discretion, to make or to select the manner of making all
necessary determinations with respect to each Option to be granted by the
Company under the Plan in addition to any other determination allowed the
Compensation Committee under the Plan including the director, employee or
officer to receive the Option. In making such determinations, the Compensation
Committee may take into account the nature of the services rendered by the
respective employees, officers, and directors, their present and potential
contributions to the success of the Company and its subsidiaries, and such
other factors as the Compensation Committee in its discretion shall deem
relevant. Subject to the provisions of the Plan, the Compensation Committee
shall also have complete authority to interpret the Plan, to prescribe, amend
and rescind rules and regulations relating to it, to determine the terms and
provisions of the respective Option Agreements (which need not be identical),
and to make all other determinations necessary or advisable for the
administration of the Plan. The Compensation Committee's determinations made in
good faith on matters referred to in this Plan shall be conclusive. Without in
any way limiting the foregoing, the Compensation Committee shall at the time
each Option is granted designate such Option as either an Incentive Option or a
Nonstatutory Option.

6.   AUTHORIZATION AND ELIGIBILITY

     Pursuant and subject to the terms of this Plan, the Compensation Committee
may grant from time to time and at any time prior to the termination of the
Plan any number of Options as the Compensation Committee shall in its
discretion determine, to any non-employee member of the Board or of any board
of directors (or similar governing authority) of any Affiliate or any employee
of or officer to one or more of the Company and its Affiliates. However, only
employees of the Company, and of any parent or subsidiary corporations of the
Company, as defined in Sections 424(e) and (f), respectively, of the Code,
shall be eligible for the grant of an Incentive Option.

     Each grant of an Option shall be subject to all applicable terms and
conditions of the Plan, and such other terms and conditions, not inconsistent
with the terms of the Plan, as the Compensation Committee may prescribe. No
prospective Participant shall have any rights with respect to a grant of
Options, unless and until such Participant has executed an agreement evidencing
the Award, delivered a fully executed copy thereof to the Company, and
otherwise complied with the applicable terms and conditions of such Award.

7.   SPECIFIC TERMS OF OPTIONS

     7.1 Date of Grant. The granting of an Option shall take place at the time
specified in the Option Agreement.

     7.2 Exercise Price. The price at which shares may be acquired under each
Incentive Option shall be not less than 100% of the Market Value of Class A

<PAGE>

Common Stock on the Grant Date, or not less than 110% of the Market Value of
Class A Common Stock on the Grant Date if the Optionee is a Ten Percent Owner.
The price at which shares may be acquired under each Nonstatutory Option shall
not be so limited solely by reason of this Section.

     7.3 Option Period. No Incentive Option may be exercised on or after the
tenth anniversary of the Grant Date, or on or after the fifth anniversary of
the Grant Date if the Optionee is a Ten Percent Owner. The Option period under
each Nonstatutory Option shall not be so limited solely by reason of this
Section.

     7.4 Exercisability. An Option may be immediately exercisable or become
exercisable in such installments, cumulative or non-cumulative, as the
Compensation Committee may determine. In the case of an Option not otherwise
immediately exercisable in full, the Compensation Committee may accelerate the
exercisability of such Option in whole or in part at any time, provided the
acceleration of the exercisability of any Incentive Option would not cause the
Option to fail to comply with the provisions of Section 422 of the Code.

     7.5 Termination of Association with the Company. Unless the Compensation
Committee shall provide otherwise in the grant of a particular Option under the
Plan, if the Optionee's employment or other association with the Company and
its Affiliates is terminated, whether voluntarily or otherwise, any outstanding
Option of the Optionee shall cease to be exercisable in any respect not later
than ninety (90) days following such termination and, for the period it remains
exercisable following termination, shall be exercisable only to the extent
exercisable at the date of termination.

     7.6 Exercise of Option. An Option may be exercised by the Optionee giving
written notice to the Company, specifying the number of shares with respect to
which the Option is then being exercised. The notice shall be accompanied by
payment in the form of cash, or certified or bank check payable to the order of
the Company in an amount equal to the exercise price of the shares to be
purchased or, if the Compensation Committee had so authorized on the grant of
any particular Option hereunder (and subject such conditions, if any, as the
Compensation Committee may deem necessary to avoid adverse accounting effects
to the Company) by delivery of that number of shares of Class A Common Stock
having a Market Value equal to the exercise price of the shares to be
purchased. Receipt by the Company of such notice and payment shall constitute
the exercise of the Option. Within 30 days thereafter but subject to the
remaining provisions of the Plan, the Company shall deliver or cause to be
delivered to the Optionee or his agent a certificate or certificates for the
number of shares then being purchased. Such shares shall be fully paid and
nonassessable. Nothing herein shall be construed to preclude the Company from
participating in a so-called "cashless exercise", provided the Optionee or
other person exercising the Option and each other party involved in any such
exercise shall comply with such procedures, and enter into such agreements, of
indemnity or otherwise, as the Company shall specify.

     7.7 Limit on Incentive Option Characterization. An Incentive Option shall
be considered to be an Incentive Option only to the extent that the number of

<PAGE>

shares of Class A Common Stock for which the Option first becomes exercisable
in a calendar year do not have an aggregate Market Value (as of the date of the
grant of the Option) in excess of the "current limit". The current limit for
any Optionee for any calendar year shall be $100,000 minus the aggregate Market
Value at the date of grant of the number of shares of Class A Common Stock
available for purchase for the first time in the same year under each other
Incentive Option previously granted to the Optionee under the Plan. Any shares
of Class A Common Stock which would cause the foregoing limit to be violated
shall be deemed to have been granted under a separate Nonstatutory Option,
otherwise identical in its terms to those of the Incentive Option.

     7.8 Notification of Disposition. Each person exercising any Incentive
Option granted under the Plan shall be deemed to have covenanted with the
Company to report to the Company any disposition of such shares prior to the
expiration of the holding periods specified by Section 422(a)(1) of the Code
and, if and to the extent that the realization of income in such a disposition
imposes upon the Company federal, state, local or other withholding tax
requirements, or any such withholding is required to secure for the Company an
otherwise available tax deduction, to remit to the Company an amount in cash
sufficient to satisfy those requirements.

8.   ADJUSTMENTS FOR CORPORATE TRANSACTIONS

     8.1. Stock Dividend, Etc. In the event of any dividend on Class A Common
Stock payable in Class A Common Stock or any split-up or contraction in the
number of shares of Class A Common Stock after the date of an Option Agreement
evidencing an Award, the remaining number of shares of Class A Common Stock
subject to such Award and the price to be paid for any share subject to the
Award, if any, shall be proportionately adjusted.

     8.2. Stock Reclassification. In the event of any reclassification or
change of outstanding shares of Class A Common Stock, immediately thereafter
(and subject to further adjustment for subsequent events) any outstanding Award
shall thereafter relate to shares of stock or other securities equivalent in
kind and value to those shares which the Participant would have received if he
or she had held of record the full remaining number of shares of Class A Common
Stock subject to the Award immediately prior to such reclassification or
change.

     8.3. Consolidation or Merger. In case of any consolidation or merger of
the Company with or into another company or in case of any sale or conveyance
to another company or entity of the property of the Company as a whole, any
outstanding Award shall terminate and, to the extent that the value of the
shares of stock, other securities or cash which a stockholder is entitled to
receive for one share of Class A Common Stock in connection with such
transaction exceeds the option price of the Award, the Optionee shall be
entitled to receive either cash or shares of stock or other securities
equivalent in kind to the cash or those shares which a holder would have
received if he or she had exercised the Award and held the number of shares of
the Class A Common Stock upon such exercise immediately prior to such
consolidation, merger, sale or conveyance and with a value equal to such excess

<PAGE>

amount multiplied by the number of shares he or she would have received if he
or she so exercised the Award at such time.

     8.4. Related Matters. Any adjustment required by this Section 8 shall be
determined and made by the Compensation Committee. No fraction of a share shall
be purchasable or deliverable upon exercise, but in the event any adjustment
hereunder of the number of shares covered by an Award shall cause such number
to include a fraction of a share, such number of shares shall be adjusted to
the nearest smaller whole number of shares. In the event of changes in the
outstanding Class A Common Stock by reason of any stock dividend, split-up,
contraction, reclassification, or change of outstanding shares of Class A
Common Stock of the nature contemplated by this Section 8, the number of shares
of Class A Common Stock available for the purposes of the Plan as stated in
Section 4 shall be correspondingly adjusted.

9.   SETTLEMENT OF AWARDS

     9.1. Investment Representation. The Company shall be under no obligation
to issue any shares covered by any Award unless the shares to be issued
pursuant to Awards granted under the Plan have been effectively registered
under the Securities Act of 1933, as amended, or the Participant shall give a
written representation to the Company which is satisfactory in form and
substance to its counsel and upon which the Company may reasonably rely, that
he or she is acquiring the shares for his or her own account for the purpose of
investment and not with a view to, or for sale in connection with, the
distribution of any such shares.

     9.2. Registration. If the Company shall deem it necessary or desirable to
register under the Securities Act of 1933, as amended or other applicable
statutes any shares of Class A Common Stock issued or to be issued pursuant to
Awards granted under the Plan, or to qualify any such shares of Class A Common
Stock for exemption from the Securities Act of 1933, as amended or other
applicable statutes, then the Company shall take such action at its own
expense.

     9.3. Tax Withholding. Whenever shares of Class A Common Stock are issued
or to be issued pursuant to Awards granted under the Plan, the Company shall
have the right to require the recipient to remit to the Company an amount
sufficient to satisfy federal, state, local or other withholding tax
requirements if, when, and to the extent required by law (whether so required
to secure for the Company an otherwise available tax deduction or otherwise)
prior to the delivery of any certificate or certificates for such shares.
However, in such cases, Participants may elect, subject to the approval of the
Compensation Committee, to satisfy the withholding requirement, in whole or in
part, by having the Company withhold shares to satisfy their tax obligations.
Participants may only elect to have Shares withheld having a Market Value on
the date the tax is to be determined equal to the minimum statutory total tax
which could be imposed on the transaction. All elections shall be irrevocable,
made in writing, signed by the Participant, and shall be subject to any
restrictions or limitations that the Compensation Committee, deems appropriate.

<PAGE>

     The obligations of the Company under the Plan shall be conditional on
satisfaction of all such withholding obligations and the Company shall, to the
extent permitted by law, have the right to deduct any such taxes from any
payment of any kind otherwise due to the recipient of an Award.

10.  NONTRANSFERABILITY OF AWARDS

     Except as otherwise provided in this Section, Awards shall not be
transferable, and no Award or interest therein may be sold, transferred,
pledged, assigned, or otherwise alienated or hypothecated, other than by will
or by the laws of descent and distribution. All of a Participant's rights in
any Award may be exercised during the life of the Participant only by the
Participant or the Participant's legal representative.

11.  LIMITATION OF RIGHTS IN STOCK; NO SPECIAL SERVICE RIGHTS

     A Participant shall not be deemed for any purpose to be a stockholder of
the Company with respect to any of the shares of Class A Common Stock issuable
pursuant to an Award, except to the extent that the Option shall have been
exercised with respect thereto and, in addition, a certificate shall have been
issued therefor and delivered to the Participant or his agent. Nothing
contained in the Plan or in any Option Agreement shall confer upon any
recipient of an Award any right with respect to the continuation of his or her
employment or other association with the Company (or any Affiliate), or
interfere in any way with the right of the Company (or any Affiliate), at any
time to terminate such employment agreement or to increase or decrease, or
otherwise adjust, the other terms and conditions of the recipient's employment
or other association with the Company and its Affiliates.

12.  TERMINATION AND AMENDMENT OF THE PLAN

     The Board may at any time terminate the Plan or make such modifications of
the Plan as it shall deem advisable. No termination or amendment of the Plan
may, without the consent of any recipient of an Award granted hereunder,
adversely affect the rights of such recipient under such Award. The
Compensation Committee may amend the terms of any Award theretofore granted,
prospectively or retroactively, provided as amended such Award is consistent
with the terms of the Plan, but no such amendment shall impair the rights of
the recipient of such Award without his or her consent.

13.  GOVERNING LAW

     The Plan and all Option Agreements and actions taken thereunder shall be
governed, interpreted and enforced in accordance with the laws of the
Commonwealth of Massachusetts, without regard to the conflict of laws
principles thereof.

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