Trademark License Agreement - Netscape Communications Corp. and Concentric Network Corp.


                          TRADEMARK LICENSE AGREEMENT

This Trademark License Agreement ('AGREEMENT') is effective as of the 23rd day
of June, 1997 ('EFFECTIVE DATE') and is entered into by and between Netscape
Communications Corporation ('NETSCAPE'), a Delaware corporation located at 501
East Middlefield Road, Mountain View California 94043, and Concentric Network
Corporation ('CONCENTRIC'), a Florida corporation located at 10590 N. Tantau
Avenue, Cupertino, California 95014.

                                    RECITALS

A.   Netscape owns and uses the names and/or trademarks NETSCAPE and NETSCAPE
     VIRTUAL OFFICE and any applications or registrations therefor as listed on
                                                                               
     Exhibit A attached hereto (collectively referred to as the 'MARKS'), in
     ---------                                                              
     connection with its Internet-related software products, services and
     technology;

B.   Concentric is in the business of offering certain Internet and Intranet-
     related services;

C.   Concentric desires to use the trademarks NETSCAPE and NETSCAPE VIRTUAL
     OFFICE solely in the titles set forth in Exhibit B in connection with
                                              ---------                   
     Intranet Service in the languages and geographic territories set forth
     opposite such titles in Exhibit B; and
                             ---------     

D.   Netscape is willing to permit such use of the Marks under the terms and
     conditions set forth in this Agreement.

NOW THEREFORE, THE PARTIES AGREE AS FOLLOWS:

1.   GRANT OF LICENSE.

     1.1  GRANT OF LICENSE.  Netscape hereby grants to Concentric a non-
exclusive, non-transferable, license to use the Marks in the title set forth in
                                                                               
Exhibit B solely in conjunction with [*] 
---------                                                                 
opposite such title (the 'INTRANET SERVICE') which Intranet Service: (a) shall
promote Netscape's products and services; (b) shall be jointly developed by
Netscape and Concentric; and (c) shall reside [*] at a location to be mutually
agreed upon by both parties deploying Concentric's servers and be located [*]
from Netscape's web site. Concentric may only use the Marks as a part of the
complete title specified in Exhibit B and shall not separately use any element
                            ---------
or elements of the Marks.

     1.2  RESERVATION OF RIGHTS.  Netscape hereby reserves any and all rights
not expressly and explicitly granted in this Agreement, including Netscape's
right to authorize or license use of the Marks or any other trademarks or names
containing NETSCAPE, to any third party for use in connection with any goods and
services, including, but not limited to, Intranet Service.  Without limiting the
rights reserved in the preceding sentence, Netscape hereby reserves any and all
rights to use, authorize use or license use of the Marks or any other trademarks
or names containing NETSCAPE in any geographic territory listed in Exhibit B in
                                                                   ---------   
a language or language(s), or in any other territory in any language, different
from the language listed next to such geographic territory in Exhibit B.  No
                                                              ---------     
right is provided to use any other Netscape trademark, including without
limitation the Netscape Horizon Logo.


[*] Certain information on this page has been omitted and filed separately 
with the Securities and Exchange Commission. Confidential treatment has been 
requested with respect to the omitted portions.


 
2.   LICENSE FEE.  For the rights granted to Concentric herein, Concentric shall
pay Netscape license fee of Five million dollars ($5,000,000) payable as
follows:

     (a) Two million dollars ($2,000,000) payable by June 30, 1997; and

     (b) Three million dollars ($3,000,000) payable by July 30, 1997.

The license fee due hereunder is exclusive of any applicable taxes.  Concentric
shall be responsible for all applicable national, state and local taxes, value
added or sales taxes, exchange, interest, banking, collection and other charges
and levies and assessments pertaining to payments other than U.S. taxes based on
Netscape's net income.  If Concentric is required by law to make any deduction
or to withhold from any sum payable to Netscape by Concentric hereunder, (i)
Concentric shall effect such deduction or withholding, remit such amounts to the
appropriate taxing authorities and promptly furnish Netscape with tax receipts
evidencing the payments of such amounts, and (ii) the sum payable by Concentric
upon which the deduction or withholding is based shall be increased to the
extent necessary to ensure that, after such deduction or withholding, Netscape
receives and retains, free from liability for such deduction or withholding, a
net amount equal to the amount Netscape would have received and retained in the
absence of such required deduction or withholding.

3.   OWNERSHIP OF MARKS.  Concentric hereby acknowledges that Netscape is the
owner of the Marks, and any trademark applications and/or registrations thereto,
agrees that it will do nothing inconsistent with such ownership and agrees that
all use of the Marks by Concentric shall solely inure to the benefit of
Netscape.  Concentric agrees that nothing in this Agreement shall give
Concentric any right, title or interest in the Marks other than the right to use
the Marks in accordance with this Agreement.  Concentric agrees not to register
or attempt to register the Marks as a trademark, service mark, Internet domain
name, trade name, or any similar trademarks or name, with any domestic or
foreign governmental or quasi-governmental authority or otherwise.  Concentric
may not register or use the Marks or an abbreviation of the Marks as part of an
Internet domain name.  The provisions of this paragraph shall survive the
expiration or termination of this Agreement.

4.   USE OF THE MARKS; PROTECTION OF THE MARKS.

     4.1  PROPER USE.  Concentric agrees that all use of the Marks shall only
occur in connection with the Intranet Service and shall be in strict compliance
with the terms of this Agreement.  Concentric may use the Marks as set forth in
Section 1.1 as well as in connection with the promotion of the Intranet Service,
excluding merchandising or any software products.  Use of the Marks for
promotional purposes shall be submitted to Netscape for approval at least twenty
(20) business days prior to the promotional use of the Mark.  The Marks shall
always be used in the English language; however the VIRTUAL OFFICE term portion
of the Mark may be translated, upon approval by Netscape, to the non-English
designated language(s) listed in Exhibit B, if any.  No other modifications to
                                 ---------                                    
the Marks shall be made.  Concentric shall use the Marks in conformance with
Netscape's trademark guidelines ('TRADEMARK GUIDELINES'), set forth in Exhibit
                                                                       -------
C, which Trademark Guidelines may be revised by Netscape from time to time.
-
Concentric agrees not to use any other trademark or service mark in combination
with the Marks other than as described in Section 1.1.  Concentric has no right
to sublicense, transfer, translate (except as provided in this Section 4.1) or
assign the use of the Marks or use the Marks for any other purpose other than
the purpose described herein.  Concentric may not use the Mark in connection
with, or for the benefit of, any third party's products or services.  Concentric
further agrees not to use the Marks on or in connection with any products or
services that are or could be deemed by Netscape, in its reasonable judgment, to
be obscene, pornographic, disparaging of Netscape or its products or products,
or otherwise in poor taste, or that are themselves unlawful or whose purpose is
to encourage unlawful activities by others.

                                       2

 
     4.2  QUALITY STANDARDS.  Concentric agrees to maintain a consistent level
of quality of the Intranet Service performed in connection with the Marks
substantially equal to that found in Concentric's existing services.  Concentric
further agrees to maintain a level of quality in connection with its use of the
Marks that is consistent with general industry standards.

     4.3  MONITORING BY NETSCAPE.  Concentric acknowledges that Netscape has no
further obligations under this Agreement other than the right to periodically
monitor Concentric's use of the Marks in conjunction with the Intranet Service.
Upon request by Netscape, Concentric shall provide Netscape with representative
samples of each such use prior to the time the Marks are utilized on the
Internet, on an Intranet or in press materials or marketing or advertising
materials.  If Netscape determines that Concentric is using the Marks
improperly, and/or in connection with Intranet Service which do not meet the
standards set forth in Section 4.1 or Section 4.2, Netscape shall notify
Concentric, and Concentric shall remedy the improper use within two (2) business
days following receipt of such notice from Netscape.  Use of the Marks on goods
or services other than the Intranet Service or the promotion of the Intranet
Service, or in a manner inconsistent with the Trademark Guidelines, shall
constitute material breach of this Agreement.  If such material breach has not
been cured within two (2) business days following receipt of notice from
Netscape, this Agreement shall be terminated.

     4.4  LEGEND; DISCLAIMER.  Concentric shall include with any online
publication or publication in print containing the Marks a trademark legend
indicating that 'Netscape is a trademark of Netscape Communications Corporation
registered in the US and in other jurisdictions and that the Marks are used
under license',  and a disclaimer that Concentric and not Netscape has produced
the Intranet Service and is responsible for the content thereof.

     4.5  NAVIGATION SERVICES.  If Netscape reasonably determines that the
[*] contain or present any material that constitutes an infringement of
Netscape's trademark, patents, copyrights or trade secrets, Concentric's right
to use the Marks pursuant to the grant described in Section 1.1 shall, upon
written notice from Netscape of such determination, be suspended until
Concentric has revised, removed or removed links to such material to
Netscape's reasonable satisfaction. If such revision or removal of, or removal
of links to, such material to Netscape's reasonable satisfaction has not
occurred within thirty (30) days of the notice from Netscape described in the
preceding sentence, Netscape may immediately terminate the license grant
described in Section 1.1. If Netscape reasonably determines that the Internet
Services contains or presents any material that could reasonably constitute an
infringement of a third party's copyright, trademark, patents or trade
secrets, Netscape may immediately terminate this Agreement if Concentric has
not revised to Netscape's reasonable satisfaction that material or
presentation within one (1) business day of written notice from Netscape.

     4.6  CONCENTRIC WEB SITES.  If Netscape, in its sole discretion, at any
time determines that [*], or any services provided by Concentric, contain any
material or present any material in a manner that Netscape reasonably deems
inaccurate or an improper tarnishment of Netscape, the Netscape products or
the Marks, or an infringement of Netscape's or a third party's rights,
including but not limited rights under trademark, patent, trade secret or
copyright laws, or unlawful in any country or territory, Netscape may
immediately terminate this Agreement if Concentric has not revised to
Netscape's reasonable satisfaction that material or presentation within three
(3) business days of written notice from Netscape; provided, however, that
Netscape's rights and Concentric's obligations under this paragraph will not
apply to material or presentations that are not within Concentric's control.

5.   CONFIDENTIAL INFORMATION AND DISCLOSURE.  Unless required by law, and
except to assert its rights hereunder or for disclosures to its own employees on
a 'need to know' basis, each party agrees not to disclose the terms of this
Agreement or matters relating thereto without the prior written consent of the
other party, which consent shall not be unreasonably withheld.

 
[*] Certain information on this page has been omitted and filed separately 
with the Securities and Exchange Commission. Confidential treatment has been 
requested with respect to the omitted portions.


                                      3

 
6.   INDEMNIFICATION.

     6.1  INDEMNIFICATION BY CONCENTRIC.  Concentric agrees to indemnify
Netscape and to hold Netscape harmless from any and all liability, loss,
damages, claims or causes of action, including reasonable legal fees and
expenses that may be incurred by Netscape, arising out of performance of this
Agreement, the operation of the Intranet Service, or Concentric's use of the
Marks and content on Concentric's web sites or services linked to or presented
or offered in conjunction with the Marks, except for liability, loss, damages,
claims or causes of action arising out of third party claims (i) that
Concentric's use of the Marks infringe that third party's valid and subsisting
U.S. trademark registration in the Marks or (ii) in respect of any act or
omission of Netscape giving rise to liability.  Netscape shall provide
Concentric with prompt written notice of any claim for which indemnification is
sought and cooperating fully with and allowing Concentric to control the defense
and settlement of such claim.  Netscape may not settle any such claim without
Concentric's prior written consent, which consent shall not be unreasonably
withheld.  Netscape shall have the right, at its own expense, to participate in
the defense of any such claim.

     6.2  INDEMNIFICATION BY NETSCAPE.  Netscape agrees to indemnify Concentric
and to hold Concentric harmless from any and all liability, loss, damages,
claims or causes of action, including reasonable legal fees and expenses that
may be incurred by Concentric, arising out of a third party claim that [*]
Concentric shall provide Netscape with prompt written notice of any claim for
which indemnification is sought and cooperating fully with and allowing
Netscape to control the defense and settlement of such claim. Concentric may
not settle any such claim without Netscape's prior written consent, which
consent shall not be unreasonably withheld. Concentric shall have the right,
at its own expense, to participate in the defense of any such claim.

7.   TERMINATION

     7.1   TERM AND TERMINATION.  [*] in Section 4.3, Section 4.5 or this
Section 7.1. Netscape shall have the right to terminate this Agreement upon
the occurrence of one or more of the following: (a) any material breach by
Concentric of its obligations under this Agreement which remains uncured for
thirty (30) days or more following written notice of such breach from
Netscape, (b) use of the Marks by Concentric in a manner which is disparaging
of Netscape or its products and services and which remains uncured for two (2)
days following notice from Netscape, (c) Concentric decides not to launch the
Intranet Service, or (d) the Intranet Service are discontinued.

     7.2   EFFECT OF TERMINATION.  Upon termination of the Agreement, 
Concentric agrees it shall immediately cease any and all use of the Marks.

8.   GENERAL

     8.1   GOVERNING LAW.  This Agreement shall be subject to and governed in 
all respects by the statutes and laws of the State of California without regard
to the conflicts of laws principles thereof. The Superior Court of Santa Clara
County and/or the United States District Court for the Northern District of
California shall have exclusive jurisdiction and venue over all controversies in
connection herewith, and each party hereby consents to such exclusive and
personal jurisdiction and venue.

     8.2   ENTIRE AGREEMENT.  This Agreement, including Exhibit A, Exhibit B, 
                                                        ---------  ---------
and Exhibit C attached hereto, constitutes the entire Agreement and
    ---------
understanding between the parties and integrates all prior discussions between
them related to its subject matter. No modification of any of the terms of this
Agreement shall be valid unless in writing and signed by an authorized
representative of each party.

[*] Certain information on this page has been omitted and filed separately 
with the Securities and Exchange Commission. Confidential treatment has been 
requested with respect to the omitted portions.


                                       4

 
     8.3   ASSIGNMENT.  Concentric may not assign any of its rights or delegate 
any of its duties under this Agreement, or otherwise transfer this Agreement (by
merger, operation of law or otherwise) without the prior written consent of
Netscape. Any attempted assignment, delegation or transfer in derogation hereof
shall be null and void.

     8.4   NOTICES.  All notices required or permitted hereunder shall be given 
in writing addressed to the respective parties as set forth below and shall
either be (a) personally delivered or (b) transmitted by nationally-recognized
private express courier, and shall be deemed to have been given on the date of
receipt if delivered personally, or two (2) days after deposit with such express
courier. Either party may change its address for purposes hereof by written
notice to the other in accordance with the provisions of this Subsection. The
addresses for the parties are as follows:

   CONCENTRIC:                            NETSCAPE:
 
   Concentric Network Corporation         Netscape Communications Corporation
   10590 N. Tantau Avenue                 501 East Middlefield Road, MV-002    
   Cupertino, CA  95014                   Mountain View, CA 94043              
   Fax: (408) 342-2876                    Fax: (415) 528-4123                  
   Attn: Mike Anthofer                    Attn: General Counsel                 
   Senior Vice President and
   Chief Financial Officer

     8.5  FORCE MAJEURE.  Neither party will be responsible for any failure to
perform its obligations under this Agreement due to causes beyond its reasonable
control, including but not limited to acts of God, war, riot, embargoes, acts of
civil or military authorities, fire, floods or accidents, provided that (a) such
party promptly notifies the other party thereof and (b) such failure does not
continue for more than three (3) days.

     8.6  WAIVER.  Any waiver, either expressed or implied, by either party of
any default by the other in the observance and performance of any of the
conditions, covenants of duties set forth herein shall not constitute or be
construed as a waiver of any subsequent or other default.

     8.7  HEADINGS.  The headings to the Sections and Subsections of this
Agreement are included merely for convenience of reference and shall not affect
the meaning of the language included therein.

     8.8  INDEPENDENT CONTRACTORS.  The parties acknowledge and agree that they
are dealing with each other hereunder as independent contractors.  Nothing
contained in the Agreement shall be interpreted as constituting either party the
joint venture or partner of the other party or as conferring upon either party
the power of authority to bind the other party in any transaction with third
parties.

     8.9  SURVIVAL. The provisions of Section 1.2 (Reservation of Rights), 3
(Ownership of Marks), 4.4 (Legend; Disclaimer), 5 (Confidential Information and
Disclosure), 6 (Indemnification), 7.2 (Effect of Termination) and 8 (General)
will survive any termination of this Agreement.

     8.10 EQUITABLE RELIEF.  Concentric recognizes and acknowledges that a
breach by Concentric of this Agreement will cause Netscape irreparable damage
which cannot be readily remedied in monetary damages in an action at law, and
may, in addition thereto, constitute an infringement of the Marks.  In the event
of any default or breach by Concentric that could result in irreparable harm to
Netscape or cause some loss or dilution of Netscape's goodwill, reputation, or
rights in the Marks, Netscape shall be entitled to immediate injunctive relief
to prevent such irreparable harm, loss, or dilution in addition to any other
remedies available.

     8.11 SEVERABILITY.  Except as otherwise set forth in this Agreement, the
provisions of this Agreement are severable, and if any one or more such
provisions shall be determined to be invalid, illegal or unenforceable, in whole
or in part, the validity, legality and enforceability of any of the remaining
provisions or portions thereof shall not in any way be affected thereby and
shall nevertheless be binding between the parties hereto.  Any such invalid,
illegal or unenforceable provision or portion thereof shall 

                                       5

 
be changed and interpreted so as to best accomplish the objectives of such
provision or portion thereof within the limits of applicable law.

     8.12 ATTORNEY'S FEES.  In the event of any action, suit, or proceeding
brought by either party to enforce the terms of this Agreement, the prevailing
party shall be entitled to receive its costs, expert witness fees, and
reasonable attorneys fees and expenses, including costs and fees on appeal.
 
IN WITNESS WHEREOF, the parties have executed this Agreement as of the


 
CONCENTRIC NETWORK CORPORATION           NETSCAPE COMMUNICATIONS CORPORATION

 
By: /s/Henry R. Nothhaft                 By: /s/ Mike Homer
   ---------------------------------         ---------------------------------- 
Name:  Henry R. Nothhaft                 Name:   Mike Homer
     -------------------------------           -------------------------------- 
Title: Pres & CEO                        Title: Senior Vice President Marketing
      ------------------------------            ------------------------------- 
Date: 6/23/97                            Date:  6/23/97
     -------------------------------            -------------------------------


Exhibit A:  Licensed Netscape Trademarks
---------
 
Exhibit B:  Titles; Target Language and Geographic Combinations
---------

Exhibit C:  Trademark Guidelines
---------

                                       6

 
                                   EXHIBIT A
                          LICENSED NETSCAPE TRADEMARKS

NETSCAPE                 U.S. FEDERAL TRADEMARK REGISTRATION NO. 2,027,552

NETSCAPE VIRTUAL OFFICE

 
                                   EXHIBIT B
              TITLES; TARGET LANGUAGE AND GEOGRAPHIC COMBINATIONS



                 Title                   Target Language        Geographic Territory
---------------------------------------  ---------------  --------------------------------
                                                     
NETSCAPE VIRTUAL OFFICE BY CONCENTRIC     [*]              [*]



[*] Certain information on this page has been omitted and filed separately 
with the Securities and Exchange Commission. Confidential treatment has been 
requested with respect to the omitted portions.


                                       2

 
                                   EXHIBIT C

TRADEMARK USE GUIDELINES


Netscape's Trademark Guidelines are published at the following URL:

     http://home.netscape.com/misc/trademarks.html#trademarks