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                                                                Exhibit 10.17


                                   ARIBA, INC.
                              1565 CHARLESTON ROAD
                         MOUNTAIN VIEW, CALIFORNIA 94043


                                November 22, 2000



Mr. Robert Calderoni
19753 Minocqua Court
Saratoga, CA  95070


Dear Bob:

                  Ariba, Inc. is pleased to offer you employment on the
following terms:

                  1.       POSITION. You will start in a full-time position
as Executive Vice President and Chief Financial Officer. You will report to
the Chief Executive Officer. By signing this letter, you confirm to Ariba
that you are under no contractual or other legal obligations that would
prohibit you from performing your duties for Ariba.

                  2.       COMPENSATION AND EMPLOYEE BENEFITS. You will be
paid a starting salary at the rate of $300,000 per annum, payable in
accordance with Ariba's standard payroll schedule. As a regular employee of
Ariba you will be eligible to participate in a number of Company-sponsored
benefits. You shall be eligible to be considered for an annual incentive
bonus (pro-rated on a fiscal year basis) with a target amount equal to
$300,000 each fiscal year. Such bonus (if any) shall be awarded in the
reasonable discretion of the Compensation Committee of the Board based on
reasonable objective or subjective criteria established in advance by the
Committee.

You will be provided with benefit choices, including medical, dental, vision,
life and disability insurance coverage for you and your dependents, as well
as participation in the 401(k) and Employee Stock Purchase Plans. The
provisions of these and other benefits offered by Ariba are explained more
fully in the Employee Benefits Summary which you will be receiving shortly.

                  3.       STOCK OPTIONS. Subject to the approval of Ariba's
Compensation Committee, you will be granted an option to purchase 875,000
shares of Ariba's Common Stock (the "First Option"). The exercise price per
share will be equal to the fair market value per share on the date the First
Option is granted or on your first day of employment, whichever is later. The
First Option will be subject to terms and conditions substantially similar to
those applicable to options granted under Ariba's 1999 Equity Incentive Plan,
as described in that Plan and the applicable stock option agreement. The
First Option will become exercisable for 25% of the First Option shares after
12 months of continuous service and the balance in equal monthly installments
over the next 36 months of continuous service, as described in the applicable
stock option agreement.



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Mr. Robert Calderoni
November 22, 2000
Page 2


Subject to the discretion of Ariba's Compensation Committee, you will be
granted an option to purchase 100,000 shares of Ariba Common Stock (the
"Second Option") at a future date. The exercise price per share will be equal
to the fair market value per share on the date the Second Option is granted.
The Second Option will be subject to terms and conditions substantially
similar to those applicable to options granted under Ariba's 1999 Equity
Incentive Plan, as described in that Plan and the applicable stock option
agreement. However, the Second Option may vest on an accelerated basis if so
determined by the Compensation Committee on the date of grant.

                  4.       PROPRIETARY INFORMATION AND INVENTIONS AGREEMENT.
You will be required to sign the Ariba Employee Agreement. In this document
you will be asked to agree to the following: 1) to hold Ariba's proprietary
information confidential during and after employment; 2) that you have not
brought any former employer's proprietary information or any of their
clients' proprietary information with you; and 3) that you will agree to
assign to Ariba any patentable inventions that you created through your work
with Ariba.

                  5.       EMPLOYMENT RELATIONSHIP. Employment with Ariba is
for no specific period of time. Your employment with Ariba will be "at will,"
meaning that either you or Ariba may terminate your employment at any time
and for any reason, with or without cause. Any contrary representations that
may have been made to you are superseded by this offer. This is the full and
complete agreement between you and Ariba on this term. Although your job
duties, title, compensation and benefits, as well as Ariba's personnel
policies and procedures, may change from time to time, the "at will" nature
of your employment may only be changed in an express written agreement signed
by you and the Chief Executive Officer of Ariba.

                  6.       OUTSIDE ACTIVITIES. While you render services to
Ariba, you agree that you will not engage in any other employment, consulting
or other business activity without the written consent of Ariba. While you
render services to Ariba, you also will not assist any person or entity in
competing with Ariba, in preparing to compete with Ariba or in hiring any
employees or consultants of Ariba. Notwithstanding the foregoing, you may
engage in charitable activities, maintain academic affiliations, board
memberships, and related activities all with a view toward maintaining and
advancing your professional and community relationships to the benefit of
Ariba, so long as such activities do not interfere with your performance of
responsibilities to Ariba. You are specifically permitted to perform
reasonable services for your former employer to assist with the transition of
your successor.

                  7.       WITHHOLDING TAXES. All forms of compensation
referred to in this letter are subject to reduction to reflect applicable
withholding and payroll taxes.

                  8.       ENTIRE AGREEMENT. This letter supersedes and
replaces any prior understandings or agreements, whether oral or written,
between you and Ariba regarding the subject matter described in this letter.



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Mr. Robert Calderoni
November 22, 2000
Page 3


                  We hope that you find the foregoing terms acceptable. You
may indicate your agreement with these terms and accept this offer by signing
and dating both the enclosed duplicate original of this letter and the
enclosed Employee Agreement and returning them to me. As required by law,
your employment with Ariba is also contingent upon your providing legal proof
of your identity and authorization to work in the United States.

                  We look forward to having you join us on November 22, 2000.

                  If you have any questions, please call me at (650) 930-6200.

                                                 Very truly yours,

                                                 ARIBA, INC.

                                                 /s/ KEITH KRACH

                                                 By:  Keith Krach
                                                 Title:  Chairman & CEO



I have read and accept this employment offer:


                  /s/ ROBERT M. CALDERONI
----------------------------------------------------
                     Signature of Robert Calderoni

Dated:            11/22/00
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ATTACHMENT
Exhibit A:  Employee Agreement