Press Release

PalmSource Schedules Second Quarter Fiscal Year 2004 Results & Conference Call For December 22

SUNNYVALE, Calif.- December 4, 2003 - PalmSource, Inc. (NASDAQ: PSRC) provider of
Palm OS, a leading operating system powering next generation mobile devices and smartphones, will release results for the second quarter of fiscal 2004 on Monday, December 22, 2003 after market close. David Nagel, president & chief executive officer and Al Wood, chief financial officer, will discuss the financial results on the second quarter conference call scheduled for 5:00 p.m. Eastern Time / 2:00 p.m. Pacific Time that same day.

A live and archived webcast will be posted on PalmSource's Web site at http://www.palmsource.com/about/ir.html. The webcast will also be distributed over CCBN's Investor Distribution Network to institutional and individual investors through CCBN's individual investor center at www.companyboardroom.com, investor sites in CCBN's Individual Investor Network and via CCBN's password-protected event management site StreetEvents at www.streetevents.com.

About PalmSource
PalmSource is the company behind Palm OS, a leading operating system powering more than 30 million Palm Powered handhelds and smartphones worldwide. Industry leaders Aceeca, AlphaSmart, Fossil, Garmin, GSL, HuneTec, Kyocera, Lenovo, palmOne, PerComm, 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 Economy. More information about PalmSource, Inc. is available on our website at
http://www.palmsource.com/, http://www.palmsource.co.uk, http://www.palmsource.fr, http://www.palmsource.de and http://www.palmsource.com.cn.

Palm OS is a registered trademark and Palm Powered is a trademark of Palm Trademark Holding Company, LLC. Other brands may be trademarks of their respective owners.