MUNICH, Germany, PalmSource™ Euro DevCon, September 28, 2004 — PalmSource, Inc. (NASDAQ: PSRC) provider of Palm OS®, a leading operating system powering next generation mobile devices and smartphones, today introduced Palm OS Cobalt 6.1, an enhanced version of Palm OS Cobalt. Designed to accelerate the development of next-generation Palm Powered™ smartphones and wireless devices, Palm OS Cobalt 6.1 builds on the foundation of Palm OS Cobalt and provides integrated telephony features, support for WiFi and Bluetooth and enhancements to the user interface. Palm OS Cobalt 6.1 offers new functionality aimed at Palm OS licensees looking to participate in the growing wireless market, while maintaining the flexibility, ease-of-use and compatibility that are the hallmarks of Palm Powered wireless devices.

"We believe Palm OS Cobalt 6.1 optimizes our platform for the creation of cutting-edge smartphones and wireless devices that are powerful yet easy-to-use," said David Nagel, president and CEO of PalmSource, Inc. "By integrating state-of-the-art wireless functionality into Palm OS, we are providing our Palm OS licensee and developer community a real time-to-market advantage in delivering smartphones and wireless mobile devices to consumers."

New features in Palm OS Cobalt 6.1

• Integrated Telephony Components — Palm OS Cobalt 6.1 now includes a standard GSM, MUX and a new GPRS API designed to make it easier and faster for hardware manufacturers to create a Palm Powered smartphone. Palm OS Cobalt 6.1 also adds standard support for NAND ROMs through an automatic backup and restore feature designed to prevent loss of user data in low power situations and during battery removal.

• Standard Support for Bluetooth and WiFi — Palm OS Cobalt 6.1 incorporates the latest Bluetooth implementation, in addition to new headset and hands-free profiles critical to the development of next generation smartphones and other wireless devices. In addition, Palm OS Cobalt 6.1 provides standard 802.11 support designed to enable device manufactures to create products with built-in WiFi.

• Standard Support for One-handed and Five-way Navigation — With built-in support for one-handed and five-way navigation, Palm OS Cobalt 6.1 paves the way for better usability and software compatibility for Palm Powered smartphones and other wireless devices. In addition, the PIM applications have been updated to take advantage of this new functionality.

• Built-in SD/IO Support — Palm OS Cobalt 6.1 provides standard SD/IO support designed to enable the creation of expansion cards such as cameras, GPS systems and wireless radios for Palm Powered smart mobile devices. In addition, Palm OS Cobalt 6.1 is compliant with USB On-the-Go, a solution that facilitates compatibility between USB-enabled mobile devices.

• Enhanced User Interface — Newly designed user interface features in Palm OS Cobalt 6.1 give many applications a new modern look and feel. Palm OS Cobalt 6.1 also introduces a Preferences application designed to enable a user to manage numerous individual settings and preferences in one central location. In addition, Palm OS Cobalt 6.1 is designed to encourage new categories of Palm Powered wireless devices by supporting QVGA, HVGA and VGA display resolutions in both portrait and landscape orientations.

• Chinese Language Support — Palm OS Cobalt 6.1 incorporates support for Simplified Chinese to enable new Palm Powered mobile products aimed at the growing China mobile market.

About PalmSource
PalmSource, Inc. is the company behind Palm OS, a leading operating system powering mobile information devices. Approximately 35 million Palm Powered handhelds and smartphones have been sold to date worldwide. Industry leaders Aceeca, AlphaSmart, Fossil, Garmin, GSL, Kyocera, Lenovo, palmOne, QTech, 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 and www.palmsource.com.cn.

Copyright © 2004, PalmSource, Inc. PalmSource and Palm OS are trademarks or registered trademarks of PalmSource, Inc. or its affiliate in the United States, France, Germany, Japan, the United Kingdom, and other countries. All other brands, product names, company names, trademarks and service marks are the properties of their respective owners. All rights reserved.

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 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 regarding the features, functions and benefits of Palm OS Cobalt 6.1 and the next generation of Palm Powered devices. 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 ability of Palm OS Cobalt 6.1 to operate free from defects and to provide the anticipated benefits including, without limitation the telephony features, wireless support and user interface enhancements required by Palm OS licensees to deliver Palm Powered products that meet end user demands while maintaining the flexibility, ease-of-use, and compatibility that are the hallmarks of Palm Powered wireless devices; the ability of Palm OS Cobalt 6.1 to provide Palm OS licensees a real time-to-marked advantage; the ability of Palm OS licensees to bring to market next generation Palm Powered smartphones and new categories of wireless devices that meet end user demands in a timely fashion; the continued growth of the wireless market and the penetration of the market by PalmSource and its licensees; the ability of PalmSource and its licensees to benefit from the anticipated growth in the Chinese mobile market; 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 Annual Report on Form 10-K for the period ended May 28, 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.