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Exhibit 10.18

NONEXCLUSIVE END-USER SOFTWARE

LICENSE AGREEMENT

BETWEEN

THE REGENTS OF THE UNIVERSITY OF CALIFORNIA

AND

ACCURAY, INC.

OFFICIAL USE ONLY

May be exempt from public release under the Freedom of Information Act
(5 U.S.C. 552), exemption number and category:
Exemption 4, Commercial/Proprietary Information
Department of Energy review required before public release
Name/Org: Sharon Trujillo, TT Division Date: August 29, 2005
Guidance (if applicable)

Confidential treatment has been requested for portions of this exhibit. The copy filed herewith omits the information subject to the confidentiality request. Omissions are designated as [*]. A complete version of this exhibit has been filed separately with the Securities and Exchange Commission.

License Agreement No. 05-C01862

TABLE OF CONTENTS

THIS DOCUMENT IS FOR NEGOTIATION PURPOSES ONLY AND DOES NOT
CONSTITUTE AN AGREEMENT BETWEEN THE PARTIES
OUO

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License Agreement No. 05-C01862

NON-EXCLUSIVE SOFTWARE LICENSE AGREEMENT

THIS LICENSE AGREEMENT, hereinafter referred to as "License Agreement" is entered into by and between THE REGENTS OF THE UNIVERSITY OF CALIFORNIA, a nonprofit educational institution and a public corporation of the State of California having its principal office at 1111 Franklin Street, Oakland, CA 94607, hereinafter referred to as the "University," and Accuray Inc., 1310 Chesapeake Terrace, Sunnyvale, CA 94089 hereinafter referred to as the "Licensee," the parties to this License Agreement being referred to individually as a "Party," and collectively as "Parties."

The University conducts research and development at Los Alamos National Laboratory for the U.S. Government under Contract No. W-7405-ENG-36, hereinafter referred to as the "Contract," with the U.S. Department of Energy, hereinafter referred to as the "DOE".

Rights in inventions, technical data and software made in the course of the University's research and development at Los Alamos National Laboratory are governed by the terms and conditions of the Contract.

Certain electron-linac particle-dynamics software entitled "PARMELA", Version 3, has been developed in the course of the University's research and development at Los Alamos National Laboratory.

The University desires that such software be developed and utilized to the fullest extent possible so as to enhance the accrual of economic and technological benefits to the U.S. domestic economy, and is therefore willing to grant an nonexclusive license to the Licensee in the Intellectual Property Rights that protect the software.

The Licensee desires to obtain from the University certain nonexclusive rights for the commercial use of the software.

Now, therefore, the Parties agree as follows:

1.     DEFINITIONS

1.1

"Licensed Software" means the computer software and related documentation identified in Appendix A.

1.2

"Intellectual Property Rights" means rights assertable by the University in the Licensed Software under U.S. or foreign laws including, but not limited to, copyright statutes, patent statutes, or other applicable laws.

1.3

"Authorized Site(s)" means any location owned or controlled by Licensee identified in Appendix C of this License Agreement but excluding all other locations where the Licensee may have research or administrative facilities or office.

2.     GRANT

2.1

Except as otherwise provided herein, the University hereby grants to the Licensee the personal, non-transferable, and nonexclusive right and license under the University's INTELLECTUAL PROPERTY RIGHTS for use at the Authorized Site(s) to perform the following:

(a)

To install the Licensed Software on an Authorized Site(s) as described in Appendix C, which is incorporated herein by reference;

1

(b)

To use, execute, reproduce, perform publicly and display publicly the Licensed Software, in executable form only, on the Authorized Site for the sole purpose of serving the internal needs of Licensee's business;

(c)

To make copies of the Licensed Software as necessary for the foregoing purpose, and one copy solely for non-productive back-up purposes in accordance with Licensee's standard procedures, provided that the Licensee accounts for such copies;

2.2

Any use, copying or distribution of the Licensed Software not authorized by this License Agreement shall automatically terminate Licensee's right and license hereunder. This grant shall be limited to use of the Licensed Software with Authorized Site(s) and by Authorized Users only. Use of the Licensed Software on processors accessible through communications networks through terminal and devices not on premises owned or controlled by the Licensee is prohibited unless otherwise agreed to in writing by the University.

2.3

The license and right granted in Article 2.1 shall be subject to the following limited license granted by the University to the U.S. Government:

For a period of five years from the date permission to assert copyright is granted to the University, the University grants to the Government, and others acting on behalf of the Government, a paid-up, non-exclusive, irrevocable worldwide license in the Licensed Software to reproduce, prepare derivative works, and perform publicly and display publicly, by or on behalf of the Government. Upon the request of Licensee, and with DOE and University approval, this period is renewable for additional five-year periods. Following the expiration of this period or periods, the University grants to the Government, and others acting on behalf of the Government, a paid-up, non-exclusive, irrevocable worldwide license in the Licensed Software to reproduce, prepare de