GPE

GPE (an acronym for GNOME Palmtop Environment or GNU Palmtop Environment depending on whom you ask) is a graphical user interface environment for handheld computers, such as palmtops and personal digital assistants (PDAs), running the Linux operating system. GPE is a complete environment of software components and applications which makes it possible to use a Linux handheld for tasks such as personal information management (PIM), audio playback, email, and web browsing.

Available under the terms of the GNU General Public License and the GNU Lesser General Public License, GPE is free software.

Read more about GPE:  Supported Devices, Development, Linux Distributions, Controversy