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                                                                     Exhibit 4.1

                       AMENDMENT NO. 4 TO RIGHTS AGREEMENT

       This Amendment No. 4 (this "Amendment") to the Rights Agreement dated as
of January 26, 1998, as amended by Amendment No. 1 dated as of February 17,
1999, Amendment No. 2 dated as of March 20, 2001 and Amendment No. 3 dated as of
May 25, 2001 (as amended, the "Rights Agreement") by and between Open Market,
Inc., a Delaware corporation (the "Company") and Fleet National Bank (formerly
known as BankBoston, N.A.), a national banking association, as Rights Agent (the
"Rights Agent"), is entered into by the Company and the Rights Agent as of
August 15, 2001. Capitalized terms not otherwise defined in this Amendment shall
have the meanings ascribed to them in the Rights Agreement.

       WHEREAS, no Stock Acquisition Date has occurred;

       WHEREAS, pursuant to Section 27 of the Rights Agreement, the Company and
the Rights Agent may from time to time supplement or amend the Rights Agreement
in accordance with the provisions of Section 27 thereof if the Company so
directs;

       WHEREAS, the Company proposes to enter into an Agreement and Plan of
Merger (the "divine Merger Agreement"), among divine, inc., a Delaware
corporation ("divine"), [Merger Sub Inc.], a Delaware corporation and a direct
wholly-owned subsidiary of divine, and the Company;

       WHEREAS, the Board of Directors of the Company has determined that the
divine Merger Agreement and the terms and conditions set forth therein and the
transactions contemplated thereby, including, without limitation, the Merger (as
defined in the divine Merger Agreement), are fair to and in the best interests
of the Company and its shareholders; and

       WHEREAS, the Board of Directors of the Company has determined, in
connection with its contemplation of the divine Merger Agreement, that it is
necessary and desirable to amend the Rights Agreement to exempt the divine
Merger Agreement and the transactions contemplated thereby, including, without
limitation, the Merger, from the application of the Rights Agreement as set
forth in this Amendment.

       NOW, THEREFORE, the Company hereby amends the Rights Agreement as
follows:

       1. Section 1(a) of the Rights Agreement is hereby amended and restated to
read in its entirety as follows:

       "(a) "Acquiring Person" shall mean any person who or which, together with
all Affiliates and Associates of such Person, shall be the Beneficial Owner of
18% or more of the shares of Common Stock then outstanding, but shall not
include (i) the Company, (ii) any Subsidiary of the Company, (iii) any employee
benefit plan of the Company or of any Subsidiary of the Company, (iv) any Person
or entity organized, appointed or established by the Company for or pursuant to
the terms of any such plan or (v) an Exempted Person. Notwithstanding anything
in this Rights Agreement to the contrary, neither divine, inc., a Delaware
corporation ("divine"), nor DI1 Acquisition Corporation, a Delaware corporation
and a wholly-owned subsidiary of

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divine ("Sub") nor any of divine's Affiliates or Associates shall become an
Acquiring Person as a result of the approval, execution, delivery or performance
of (i) the Agreement and Plan of Merger, dated as of August 15, 2001, among
divine, Sub and the Company (as it may be amended or supplemented from time to
time, the "divine Merger Agreement"), (ii) the Company Stockholders Agreements
(as defined in the divine Merger Agreement), as such Company Stockholders
Agreements may be amended or supplemented from time to time with the consent of
the Company, (iii) the Credit Agreement, dated as of August 15, 2001, between
the Company and divine (the "Credit Agreement") or (iv) the consummation of the
transactions contemplated thereby, including the Merger (as defined in the
divine Merger Agreement) or the conversion of outstanding Loans (as defined in
the Credit Agreement) and accrued and unpaid interest thereon into Common Stock
in accordance with the terms of the Credit Agreement (such approval, execution,
delivery, performance and consummation being referred to herein as the
"Permitted Events"). Notwithstanding any of the foregoing, no Person shall
become an "Acquiring Person" as the result of an acquisition of Common Stock by
the Company which, by reducing the number of shares outstanding, increases the
proportionate number of shares beneficially owned by such Person to 18% or more
of the Common Shares of the Company then outstanding; PROVIDED, HOWEVER, that if
a Person shall become the Beneficial Owner of 18% or more of the shares of
Common Stock of the Company then outstanding by reason of share purchases by the
Company and shall, after such share purchases by the Company, become the
Beneficial Owner of any additional Common Stock of the Company, then such Person
shall be deemed to be an "Acquiring Person". Notwithstanding the foregoing, if
the Board of Directors of the Company determines in good faith that a Person who
would otherwise be an "Acquiring Person" as defined pursuant to the foregoing
provisions of this paragraph (a), has become such inadvertently, and such Person
divests as promptly as practicable a sufficient number of shares of Common Stock
so that such Person would no longer be an "Acquiring Person," as defined
pursuant to the foregoing provisions of this paragraph (a), then such Person
shall not be deemed to be an "Acquiring Person" for any purposes of this
Agreement unless and until such Person shall again become an "Acquiring
Person"."

       2. Section 1(dd) of the Rights Agreement is hereby amended and
supplemented by adding the following sentence to the end thereof:

"Notwithstanding anything in this Rights Agreement to the contrary, a Stock
Acquisition Date shall not occur or be deemed to occur as a result of any
Permitted Event."

       3. Section 1(ii) of the Rights Agreement is hereby amended and restated
in its entirety as follows:

       "(ii) "Exempted Person" shall mean (i) The Palladin Group, L.P. and
Gleneagles Fund Company, and each of their respective Affiliates and Associates
(collectively, the "Palladin Entities"), unless and until such time as the
Palladin Entities directly or indirectly become the Beneficial Owner of Common
Stock in excess of the Palladin Exempt Threshold. For purposes of this
Agreement, the Palladin Exempt Threshold shall mean that percentage of the
Common Stock equal to the sum of that percentage of shares of Common Stock then
outstanding represented by shares received (A) as a dividend on or as a result
of any conversion or redemption of, shares of the Company's Series E 6%
Cumulative Convertible Preferred Stock,

                                      -2-

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$.10 par value per share, (B) pursuant to the Purchase Agreement, dated as of
March 20, 2001, between the Company and certain of the Palladin Entities, and
the agreements referred to therein including the Registration Rights Agreement,
the Common Stock Warrant and the Adjustment Warrant, each dated as of March 20,
2001, or (C) pursuant to the Waiver and Modification Agreement, dated as of
August 16, 2001, between the Company and certain of the Palladin Entities, and
(ii) Theddingworth International Limited and its Affiliates and Associates
(collectively, "Theddingworth"), unless and until such time as Theddingworth
directly or indirectly becomes the Beneficial Owner of Common Stock in excess of
the Theddingworth Exempt Threshold. For purposes of this Agreement, the
Theddingworth Exempt Threshold shall mean that percentage of the Common Stock
equal to the sum of that percentage of shares of Common Stock then outstanding
represented by shares received pursuant to the Common Stock Purchase Agreement,
dated as of May 25, 2001, between the Company and Theddingworth, and the
agreements referred to therein including the Registration Rights Agreement, the
Escrow Agreement and the Stock Purchase Warrant, each dated as of May 25, 2001."

       4. Section 3(a) of the Rights Agreement is hereby amended and
supplemented by adding the following sentence to the end thereof:

       "Notwithstanding anything in this Rights Agreement to the contrary, a
Distribution Date shall not occur or be deemed to occur as a result of any
Permitted Event."

       5. Section 1(o) of the Rights Agreement is hereby amended by deleting it
and replacing it with the following:

       "(o) "Final Expiration Date" shall mean the earlier of (x) January 26,
2008 and (y) the closing of the transactions contemplated by the divine Merger
Agreement."

       6. Section 15 of the Rights Agreement is hereby amended and supplemented
by adding the following sentence to the end thereof:

"Nothing in this Agreement shall be construed to give any holder of Rights or
any other Person any legal or equitable right, remedy or claim under this
Agreement in connection with a Permitted Event."

       6. This Amendment shall be deemed to be a contract made under the laws of
the State of Delaware and for all purposes shall be governed by and construed in
accordance with the laws of such State applicable to contracts to be made and
performed entirely within such State.

       7. This Amendment may be executed in any number of counterparts, each of
such counterparts shall for all purposes be deemed an original and all such
counterparts shall together constitute but one and the same instrument.

       8. This Amendment shall be deemed effective as of the date first set
forth above and immediately prior to the execution of the divine Merger
Agreement. In all respects not inconsistent with the terms and provisions of
this Amendment, the Rights Agreement is hereby ratified, adopted, approved and
confirmed. In executing and delivering this Amendment, the

                                      -3-

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Rights Agent shall be entitled to all the privileges and immunities afforded to
the Rights Agent under the terms and conditions of the Rights Agreement.

       9. If any term, provision, covenant or restriction of this Amendment is
held by a court of competent jurisdiction or other authority to be invalid, void
or unenforceable, the remainder of the terms, provisions, covenants and
restrictions of this Amendment, and of the Rights Agreement, shall remain in
full force and effect and shall in no way be affected, impaired or invalidated.

       10. Except as otherwise expressly provided herein, or unless the context
otherwise requires, all terms used herein have the meanings assigned to them in
the Rights Agreement.

                [remainder of this page intentionally left blank]

                                      -4-

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       IN WITNESS WHEREOF, the parties have caused this Amendment No. 4 to the
Rights Agreement to be executed in counterparts as of the date first written
above.

ATTEST:                                  OPEN MARKET, INC.

/s/ Edward Durkin                        By: /s/ Harland LaVigne
-----------------------------------         -----------------------------------
Name:  Edward Durkin                        Name:  Harland LaVigne
Title: Chief Financial Officer              Title: Chairman of the Board and
                                                   Chief Executive Officer

[Seal]

ATTEST:                                  FLEET NATIONAL BANK

/s/ Vina LaFontant                       By: /s/ Carol Mulvey-Eori
-----------------------------------         -----------------------------------
Name:  Vina LaFontant                       Name:  Carol Mulvey-Eori
Title: Account Manager                      Title: Directing Manager

[Seal]Prepared by MERRILL CORPORATION

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Exhibit 4.8    
  

	NUMBER

NYU 79955	 	THIS CERTIFICATE IS

TRANSFERABLE IN

SAN FRANCISCO

OR NEW YORK	 	

 	 	COMMON STOCK

SHARES
	 	 	See reverse for certain definitions and statements of rights granted to each class of shares	 	INCORPORATED UNDER THE LAWS OF THE STATE OF DELAWARE	 	CUSIP 170040 10 9
	

 	
 	

This Certifies That	
 	
SPECIMEN	
 	

 
	
 	
 	

is the owner of	
 	

 	
 	

 
	 	 	FULLY PAID AND NON-ASSESSABLE SHARES OF THE COMMON STOCK, PAR VALUE $.01 PER SHARE, OF
	 	 	CHIRON CORPORATION
	 	 	transferable on the books of the Corporation by the holder hereof, in person or by duly authorized attorney, upon surrender of this certificate properly endorsed.
	 	 	This certificate is not valid until countersigned by the Transfer Agent and registered by the Registrar.
	 	 	Witness the facsimile seal of the Corporation and the facsimile signatures of its duly authorized officers.
	

 	
 	

Dated:	
 	

 

President and

Chief Executive Officer	
 	

 

Secretary
	

 	
 	

[SEAL]	
 	

 	
 	

Countersigned and Registered:

WELLS FARGO BANK MINNESOTA, N.A.

Transfer Agent and Registrar
	

 	
 	

 	
 	

 	
 	

By: 
 Authorized Signature

CHIRON CORPORATION  

    This Certificate and the shares represented hereby are subject to the laws of the State of Delaware and to the provisions of the Articles of Incorporation of
the Corporation as amended from time to time. The record holder of this Certificate may obtain from the Secretary of the Corporation, upon request and without charge, a copy of the statement of the
rights, preferences, privileges and restrictions granted to or imposed upon each class or series of capital stock of the Corporation and upon the holders thereof, the number of shares constituting
each class or series and the designation thereof. 

    The
following abbreviations, when used in the inscription on the face of this certificate, shall be construed as though they were written out in full according to applicable laws or
regulations: 

	TEN COM	 	—	 	as tenants in common	 	UNIF GIFT MIN ACT—	 	................ Custodian	 	................
	 	 	 	 	 	 	 	 	(Cust)        	 	(Minor)
	TEN ENT	 	—	 	as tenants by the entireties	 	 	 	under Uniform Gifts to Minors
	JT TEN	 	—	 	as joint tenants with right of	 	 	 	 	 	 
	 	 	 	 	survivorship and not as tenants	 	 	 	Act................................................
	 	 	 	 	in common	 	 	 	   (State)

Additional abbreviations may also be used though not in the above list. 

For
Value Received,                 hereby sell, assign and transfer unto 

	 	 	PLEASE INSERT SOCIAL SECURITY OR OTHER	 	 
	 	 	IDENTIFYING NUMBER OF ASSIGNEE	 	 
	

	
	 	 	 	

	
	 	 	 	

	
	 	 	 	

	
	 	 	 	

	

	

	(PLEASE PRINT OR TYPEWRITE NAME AND ADDRESSS, INCLUDING ZIP CODE, OF ASSIGNEE)
	

	

	

	
 	

Shares

of the Common Stock represented by the within certificate, and do hereby irrevocably constitute and appoint
                                         
       
Attorney to transfer the said shares on the books of the within named Corporation with full power of substitution in the premises. 

  Dated
                             

	 	 	
NOTICE:  THE SIGNATURE TO THIS ASSIGNMENT MUST CORRESPOND WITH THE NAME AS WRITTEN UPON THE FACE OF THE CERTIFICATE, IN EVERY PARTICULAR, WITHOUT ALTERATION OR ENLARGEMENT
OR ANY CHANGE WHATEVER.

Signature(s) Guaranteed: 

	
 THE SIGNATURES(S) SHOULD BE GUARANTEED BY AN ELIGIBLE GUARANTOR INSTITUTION (BANKS, STOCKBROKERS, SAVINGS AND LOAN ASSOCIATIONS AND CREDIT UNIONS WITH MEMBERSHIP IN AN APPROVED MEDALLION SIGNATURE GUARANTEE
PROGRAM), PURSUANT TO S.E.C. RULE 17Ad-15	 	 

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Exhibit 4.8

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