Press Release

PalmSource Schedules Q3 FY05 Conference Call

SUNNYVALE, Calif., March 18, 2005 — PalmSource Inc., (NASDAQ: PSRC) provider of Palm OS®, a leading operating system powering next generation phones and mobile devices, will announce its third quarter FY05 results on Thursday, March 31, after market close, followed by a conference call at 5:00 p.m. EST (2:00 p.m. PST).

The conference call will be hosted by David Nagel, president and chief executive officer, Jeanne Seeley, chief financial officer, and Ira Cook, vice president of finance.

A live Web cast of the conference call will be available on PalmSource 's investor relations Web site at www.palmsource.com/about/ir.html and will be available until May 20, 2005.

A replay of the conference call will be available through April 7, 2005. The replay number for the call will be 800–642–1687 (domestic) and 706–645–9291 (international). The passcode will be 4786093.

About PalmSource
PalmSource, Inc. is the company behind Palm OS®, a leading operating system powering mobile information devices. Approximately 38 million Palm Powered™ handhelds and smartphones have been sold to date worldwide. Industry leaders Aceeca, AlphaSmart, Fossil, Garmin, GSL, Kyocera, Lenovo, palmOne, PiTech, Samsung, Sony, Symbol Technologies and Tapwave license Palm OS to create diverse mobile devices that meet unique customer needs. Palm OS has given rise to a large community of users, enterprises, developers and manufacturers, who together make up the Palm Powered Economy. More information about PalmSource is available at www.palmsource.com, www.palmsource.co.uk, www.palmsource.fr, www.palmsource.de, www.palmsource.com/es and www.palmsource.com.cn.

Copyright © 2005, PalmSource, Inc. PalmSource, Palm OS, Palm Powered, and certain other trademarks and logos appearing on this press release are trademarks or registered trademarks of PalmSource, Inc. or its affiliate in the United States, France, Germany, Japan, the United Kingdom, and other countries. These marks may not be used in connection with any product or service that does not belong to PalmSource, Inc. (except as expressly permitted by a license with PalmSource, Inc.), in any manner that is likely to cause confusion among customers, or in any manner that disparages or discredits PalmSource, Inc., its licensor, its subsidiaries or affiliates. All other brands and trademarks used herein are or may be trademarks of, and are used to identify other products or services of, their respective owners. All rights reserved.