KYAK Kayak Software Corp. - Class A (MM)

2004 Stock Incentive Plan

(Full Title of the Plans)

Karen Ruzic Klein

General Counsel and Corporate Secretary

KAYAK Software Corporation

55 North Water Street, Suite 1

Norwalk, CT 06854

(203) 899-3100

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copy to:

Michael A. Conza

Bingham McCutchen LLP

One Federal Street

Boston, MA 02110

Tel: (617) 951-8000

Fax: (617) 951-8736

Indicate by check mark whether the Registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See definitions of “large accelerated filer,” “accelerated filer,” and “smaller reporting company” in Rule 12b-2 of the Exchange Act. (Check one):

DEREGISTRATION OF COMMON STOCK

On August 31, 2012, KAYAK Software Corporation (the “Registrant”) filed with the Securities and Exchange Commission (the “Commission”) a registration statement on Form S-8, Registration No. 333-183664 (the “Registration Statement”), for the sale of (i) 1,100,000 shares of Class A and Class B common stock, both with par value $0.001 per share, of the Registrant (the “Class A common stock” and “Class B common stock” respectively and together the “Common Stock”) under the Registrant’s 2012 Equity Incentive Plan, (ii) 9,849,769 shares of each of Class A common stock and Class B common stock under the Registrant’s Third Amended and Restated 2005 Equity Incentive Plan, and (iii) 621,914 shares of each of Class A common stock and Class B common stock under the Registrant’s 2004 Stock Incentive Plan.

The Registrant is filing this Post-Effective Amendment No. 1 to Form S-8 to withdraw and remove from registration the uninssued and unsold shares of the Registrant’s Common Stock previously registered by the Registrant pursuant to the Registration Statement.

On May 21, 2013, pursuant to the terms of the Agreement and Plan of Merger, dated as of November 8, 2012, by and among priceline.com Incorporated (“priceline.com”), the Registrant, and Produce Merger Sub, Inc. (“Produce”), a wholly owned subsidiary of priceline.com, the Registrant merged with and into Produce, and the Registrant became an indirect wholly-owned subsidiary of priceline.com (the “Merger”). At the effective time of the Merger, each outstanding and unexercised option, whether vested or unvested, was automatically converted into (1) an option to purchase a number of shares of priceline.com common stock subject to a formula more fully described in the Proxy Statement/Prospectus filed with the Commission by priceline.com on February 4, 2012 (the “Prospectus”) and (2) an amount in cash equal to an amount more fully described in the Prospectus. At the effective time of the Merger, any vesting conditions applicable to each outstanding restricted stock unit accelerated in full and each restricted stock unit was cancelled and the holders received an amount in cash equal to $41.40 per restricted stock unit.

As a result of the Merger, the offerings pursuant to the Registration Statement have been terminated. In accordance with an undertaking made by the Registrant in the Registration Statement to remove from registration, by means of a post-effective amendment, any of the Common Stock registered under the Registration Statement that remain unsold at the termination of the offerings, the Registrant hereby removes from registration the Common Stock registered but unsold under the Registration Statement.