Employment Agreement - Ariba Inc. and Robert Calderoni


                                   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.






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.






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 
        --------------------------------------------



ATTACHMENT
Exhibit A:  Employee Agreement