Press Release

Enterprise Application Development for Palm OS Gains Momentum

Over 100,000 Registered Palm OS Enterprise Developers To Date

SUNNYVALE, Calif., June 30, 2004 — PalmSource, Inc. (NASDAQ: PSRC) provider of Palm OS™, a leading operating system powering next generation mobile devices and smartphones, today announced the number of registered enterprise Palm OS developers has surpassed 100,000, with over 12,000 new enterprise developers registered in the last six months.

"We believe Palm OS is driving greater adoption of smart mobile devices in the enterprise market, " said David Nagel, president and CEO of PalmSource. "Combining Palm Powered smart mobile devices and enterprise applications offers a powerful solution for enterprises to stay connected to mission critical information."

The power and flexibility of the Palm OS platform continues to attract a large and loyal following of third-party developers looking to optimize their Palm OS application development for the growing mobile market. Registered enterprise developers building mobile applications for Palm Powered mobile devices span essential business processes, including customer relationship management (CRM), sales force automation (SFA), supply chain management (SCM) and mobile field service.

"The stability, familiarity and ease with which third-party applications can be developed for the Palm OS platform make it an extremely viable choice for enterprises looking to go wireless," said Alex Klyce, executive vice president of Sendia Corporation, a wireless application developer based in Santa Monica, Calif. (www.sendia.com). "Our Wireless Salesforce Automation application, which extends salesforce.com's CRM solution to the mobile environment, has performed flawlessly when extended to the Palm OS platform, and we've received very positive feedback from Sendia's enterprise customers who are currently using our solution on the Treo™ 600 smartphone from palmOne."

Mobile computing has emerged as one of the key priorities for businesses seeking to facilitate mobile workforce productivity and ensure a higher return on investment (ROI). Palm OS is the most widely accepted mobile data operating system, appearing on 88 percent of enterprise mobile computing standards lists¹. Today's next generation Palm Powered smart mobile devices are helping companies in vertical industries improve the way they do business. Palm Powered mobile devices meet user requirements for ease of use, personalization and elegance while delivering on enterprise demands for flexibility, security, and interoperability with existing IT infrastructure.

About PalmSource
PalmSource, Inc. is the company behind Palm OS, a leading operating system powering mobile information devices. Approximately 33 million Palm Powered handhelds and smartphones have been sold to date worldwide. Industry leaders Aceeca, AlphaSmart, Fossil, Founder Technology, Garmin, GSL, Kyocera, Lenovo, palmOne, PerComm, Samsung, Sony, Symbol Technologies and Tapwave license Palm OS to create diverse mobile devices that meet unique customer needs. Hardware manufacturers choose Palm OS because it provides a flexible and efficient platform that enables them to rapidly and efficiently create a wide range of powerful, innovative and easy-to-use Palm Powered mobile devices including, handhelds, smartphones, high-end multimedia, industrial and game devices.

Palm, Palm OS, PalmSource, palmOne and Palm Powered are trademarks of Palm Trademark Holding Company, LLC. Treo is among the trademarks or registered trademarks owned by or licensed to palmOne, Inc. or its subsidiaries.

Safe Harbor Statement
CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS: This press release contains forward-looking statements that involve risks and uncertainties, as well as assumptions that, if they never materialize or prove incorrect, could cause our results to differ materially from those expressed or implied by such forward-looking statements. Such forward-looking statements include, without limitation, statements related to the adoption of smart mobile devices in the enterprise market; the features and benefits of Palm Powered smart mobile devices, enterprise applications, and the Palm OS platform; and the Palm OS enterprise developer community. The risks and uncertainties that could cause our results to differ materially from those expressed or implied by such forward-looking statements include, without limitation, the our ability to maintain and grow the Palm OS enterprise developer community; the ability of Palm OS enterprise developers to create applications, in a timely manner, that meet end user requirements and that are accepted in the market; the ability of Palm OS applications and Palm Powered devices to operate free from programming errors and defects; the ability of the Palm OS platform to provide the anticipated power and flexibility required to attract and maintain the Palm OS developer community; the adoption of Palm Powered solutions in the enterprise market; our ability to benefit from any growth in the smartphone and mobile device markets in general and more particularly in the enterprise market; and the general economic conditions in the U.S. and abroad and other risks and uncertainties contained in our public announcements, reports to stockholders and other documents filed with and furnished to the Securities and Exchange Commission, including our Quarterly Report on Form 10-Q for the period ended August 29, 2003, November 28, 2003 and February 27, 2004. All forward-looking statements in this press release are based on information available to us as of the date hereof, and we assume no obligation to update these forward-looking statements.

¹Enterprise study, Mindwave Research and Customer Insights, 2003.