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                                                                   EXHIBIT 10.26
                       ASSIGNMENT AND ASSUMPTION OF LEASE


     THIS ASSIGNMENT AND ASSUMPTION OF LEASE (this "Assignment"), made as of the
5th day of April, 2000, between ZD Inc., a Delaware corporation, having an
office at 28 East 28th Street, New York, New York 10016 ("Assignor"), and
Ziff Davis Publishing Inc., a Delaware corporation, having an office c/o Willis
Stein & Partners II, L.P., 227 West Monroe Street, Chicago, Illinois 60606
("Assignee").

                              W I T N E S S E T H:

     WHEREAS, by that certain Lease dated as of January 15, 1998, between 63
Madison Associates, L.P. ("Landlord"), as landlord, and Ziff-Davis Inc. n/k/a ZD
Inc., as tenant, as amended by letter agreement dated September 23, 1999 between
Landlord and Assignor (collectively, the "Lease"), Landlord is leasing to
Assignor Concourse Level "B-2" and the entire 8th, 9th, 10th, 11th, 12th, 13th,
14th and 15th floors (collectively, the "Premises") of the building (the
"Building") known as 63 Madison Avenue, New York, New York 10016 as more
particularly described on Schedule 1 annexed hereto;

     WHEREAS, by that certain Sublease dated March 16, 2000 between Assignor, as
sublandlord, and Softbank Inc., as subtenant (the "15th Floor Sublease"),
Assignor is subleasing to Softbank Inc. the entire 15th floor of the Building on
the terms and conditions described therein;

     WHEREAS, by that certain Sublease dated March 10, 2000 between Assignor, as
sublandlord, and Ziff-Davis Inc., as subtenant (the "10th Floor Sublease" and,
collectively with the 15th Floor Sublease, the "Subleases"), Assignor is
subleasing to Ziff-Davis, Inc. the entire 10th floor of the Building on the
terms and conditions contained therein; and

     WHEREAS, Assignor desires to assign and transfer to Assignee (i) Assignor's
right, title and interest in and to the Lease subject to the Subleases and (ii)
Assignor's right, title and interest in and to the Subleases; and Assignee
desires to accept such assignment and transfer upon the terms and conditions
hereinafter set forth.

     NOW, THEREFORE, in consideration of the mutual covenants herein contained,
it is mutually agreed as follows:

     1. Assignment by Assignor. Assignor hereby assigns and transfers to
Assignee (a) all of Assignor's right, title and interest in and to the Lease
subject to the Subleases and (b) all of Assignor's right, title and interest in
and to the Subleases, in each case subject to the terms and conditions
hereinafter set forth.

     2. Effective Date of Assignment. This Assignment shall take effect on the
"Closing Date" specified in that certain Purchase Agreement dated as of December
6, 1999 between Assignor and Assignee (the "Purchase Agreement"), and Assignor
shall give possession of the Premises to Assignee on that date (the "Assignment
Date").

After recording, this Assignment should be returned to:

Roberto S. Miceli, Esq.
---------------------------------------
Kirkland & Ellis
---------------------------------------
200 East Randolph Drive
---------------------------------------
Chicago, IL 60601
---------------------------------------


     3. Acceptance and Assumption by Assignee. Assignee hereby accepts the
assignment and transfer of Assignor's right, title and interest in and to the
Lease subject to the
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Subleases and Assignor's right, title and interest in and to the Subleases and
promises to pay all rent and additional rent under the Lease and to faithfully
perform all covenants, stipulations, agreements and obligations under the Lease
and the Subleases accruing on or after the Assignment Date or otherwise
attributable to the period commencing on the Assignment Date and continuing
thereafter.

     4. Notices. Except as otherwise specifically provided herein, any notice,
statement, demand, consent, approval, advice or other communication required or
permitted to be given, rendered or made by either party to the other, pursuant
to this Assignment or pursuant to any applicable law or requirement of public
authority (collectively, "communications") shall be in writing and shall be
deemed to have been properly given, rendered or made only if sent by personal
delivery, or registered or certified mail, return receipt requested, posted in a
United States post office station in the continental United States, or by a
nationally recognized overnight courier, in each case addressed (i) to Assignor
at its address first above written, Attention: President and (ii) to Assignee,
at its address first above written, Attention: President. A copy of each
communication to Assignor shall also be sent to Clifford Chance Rogers & Wells
LLP, 200 Park Avenue, New York, New York 10166, Attention: Joanne Feil, Esq. All
such communications shall be deemed to have been given, rendered or made when
delivered on the date such communication is actually received as evidenced by a
written receipt therefor or refusal to accept delivery, as of the date of such
refusal, in the case of personal delivery, or three (3) days after the day so
mailed, or one (1) business day after sent by nationally recognized overnight
courier. Either party may, by notice as aforesaid actually received, designate a
different address or addresses for communications intended for it. Any and all
notices of default which Assignee may give to Landlord or any subtenant under
the Subleases shall simultaneously be given to Assignor. Copies of any and all
notices of default which Assignee may receive from Landlord or any subtenant
under the Subleases shall immediately be delivered to Assignor.

     5. Broker. Each party hereto covenants, warrants and represents to the
other party that it has had no dealings, conversations or negotiations with any
broker concerning the execution and delivery of this Assignment except as may
otherwise be specified in the Purchase Agreement. Each party hereto agrees to
defend, indemnify and hold harmless the other party against and from any claims
for any brokerage commissions and all costs, expenses and liabilities in
connection therewith, including, without limitation, reasonable attorneys' fees
and disbursements, arising out of its respective representations and warranties
contained in this Section being untrue. The provisions of this Section shall
survive the expiration or earlier termination of this Assignment.

     6. Costs of Assignment. All taxes and other governmental charges and fees,
if any, including, without limitation, any and all transfer taxes, stamp taxes,
sales tax and recording fees, relating to this Assignment shall be paid by the
party against whom such taxes, charges, and fees are assessed.

     7. Indemnification. Assignor and Assignee hereby reaffirm the
indemnification obligations set forth in the Purchase Agreement.

     8. Consent of Landlord. This Assignment is specifically conditioned upon
Assignor obtaining the consent of Landlord to this assignment.

     9. Successors and Assigns: Further Actions. This Assignment shall be
binding upon all successors and assigns of the parties hereto. The parties
hereto shall execute and
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deliver such further and additional instruments, agreements and other documents
which may be necessary to evidence or carry out the provisions of this
Assignment.

     10. Entire Agreement. This Assignment supersedes all agreements previously
made between the parties hereto relating to the subject matter contained herein.

     11. No Waiver. No delay or failure by any party hereto to exercise any
rights under this Assignment, and no partial or single exercise of that right,
shall constitute a waiver of that or any other right, unless otherwise expressly
provided herein.

     12. Applicable Law. This Assignment shall be construed in accordance with
and governed by the laws of the State of New York.

     13. Counterparts. This Assignment may be executed in two counterparts, each
of which shall be deemed an original, but both of which together shall
constitute one and the same instrument.

     WITNESS WHEREOF, the parties hereto have executed this Assignment on the
date first above written.

                                           ASSIGNOR:
                                           ZD INC.


                                           By:    /s/ J. MALCOLM MORRIS
                                                  ------------------------------
                                           Name:  J. Malcolm Morris
                                                  ------------------------------
                                           Title: Sr. V.P.
                                                  ------------------------------


                                           ASSIGNEE:
                                           ZIFF DAVIS PUBLISHING INC.


                                           By:    /s/ DANIEL H. BLUMENTHAL
                                                  ------------------------------
                                           Name:  Daniel H. Blumenthal
                                                  ------------------------------
                                                  President
                                                  ------------------------------
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State of New York, )
                   ) ss.:
County of New York )

     On the 4th day of April, in the year 2000 before me the undersigned
personally appeared J. Malcolm Morris, personally know to me or proved to me on
the basis of satisfactory evidence to be the individual whose name is subscribed
to the within instrument and acknowledged to me that he/she executed the same in
his/her capacity as Senior V.P. of ZD Inc., and that by his/her signature on the
instrument, the individual, or the person upon behalf of which the individual
acted, executed the instrument.

/s/ Eugene Hom                                          EUGENE HOM
--------------------------------------        NOTARY PUBLIC, State of New York
Signature and Office of individual                     No. 41-4929038
taking acknowledgment                            Qualified in Queens County
                                            Certificate filed in New York County
                                              Commission Expires June 25, 2000


State of Illinois )
                  ) ss.:
County of Cook    )

     On the 5th day of April, in the year 2000 before me the undersigned
personally appeared Daniel H. Blumenthal, personally know to me or proved to me
on the basis of satisfactory evidence to be the individual whose name is
subscribed to the within instrument and acknowledged to me that he/she executed
the same in his/her capacity as President of Ziff Davis Publishing Inc. and that
by his/her signature on the instrument, the individual, or the person upon
behalf of which the individual acted, executed the instrument.


/s/ Cynthia M. Wasik                                       [Seal]
----------------------------------------     ----------------------------------
Signature and Office of individual
taking acknowledgment                                 Cynthia M. Wasik
                                              Notary Public, State of Illinois
                                             My Commission Expires May 12, 2002
                                             ----------------------------------

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                                   Schedule 1

All that certain plot, piece or parcel of land situate, lying and being in the
Borough of Manhattan, City, County and State of New York, bounded and described
as follows:

BEGINNING at the intersection of the northerly side of East 27th Street with the
easterly side of Madison Avenue;

THENCE along said side of Madison Avenue in a northerly direction, 197 feet 6
inches to the southerly side of East 28th Street;

THENCE along said side of East 28th Street, a distance of 275 feet to a point
which is distant 150 feet westerly as measured along said side of East 28th
Street from the Westerly side of Park Avenue South;

THENCE southerly and parallel with said side of Park Avenue South 197 feet 6
inches to the northerly side of East 27th Street; and

THENCE westerly along said side of East 27th Street, a distance of 275 feet to
the point of place of BEGINNING.

TOGETHER WITH the benefits and subject to the burdens of an Agreement dated
November 20, 1995 between New York Life Insurance Company and 63 Madison
Associates, L.P. and recorded in the Office of the New York City Register's
Office on January 10, 1996 in Reel 2280 page 174.