Press Release

PalmSource Schedules Q4 and Year–End FY05 Conference Call

SUNNYVALE, Calif., June 9, 2005 — PalmSource Inc., (NASDAQ: PSRC) provider of Palm OS®, a leading operating system powering next generation phones and mobile devices, will announce its fourth quarter and Fiscal Year 2005 results on Wednesday, June 29, after market close, followed by a conference call at 5:00 p.m. EDT (2:00 p.m. PDT).

The conference call will be hosted by Patrick McVeigh, interim chief executive officer, Jeanne Seeley, chief financial officer and Brian Siegel, director of investor relations.

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 July 6, 2005.

A replay of the conference call will be available through July 6, 2005. The replay number for the call will be 800–642–1687 (domestic) and 706–645–9291 (international). The passcode will be 7015745.

About PalmSource
PalmSource, Inc., the company behind Palm OS®, a leading operating system powering smart mobile devices, is a leading developer of software for mobile phones and other mobile devices. Its products include a wide range of software for mobile phones at all price points. More than 39 million mobile phones, handhelds, and other mobile devices run PalmSource software. More than 45 companies worldwide have licenses to PalmSource software, including Fossil, Garmin, GSPDA, Kyocera, Lenovo, palmOne, Samsung, Sony, and Symbol Technologies. 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, Palm Desktop, Graffiti, HotSync and certain other trademarks and logos are trademarks which may be registered in the United States, and are either owned by PalmSource, Inc. or its affiliates in the United States, France, Germany, Japan, the United Kingdom, and other countries, or are licensed by PalmSource, Inc. from Palm Trademark Holding Company, LLC. 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.