From the 700 series Zaurus onwards, there has been sufficient processor power and memory to allow emulation of other platforms. Of course, it is quicker to provide a virtual machine/application library interface than to emulate an alien platform where the processor and peripherals are totally different from the Zaurus's.
The most exciting development as of writing this is the Zaurus port of the PSX emulator. http://www.oesf.org/forums/index.php?showtopic=17052
|Palm (68k)||Copilot||slow, only for early 68000 based Palms. Maybe when PalmOs 6 comes out, which is linux based, there will be progress?||http://hewgill.com/pilot/copilot/|
|Palm (68k)||qpose||slow, only for early 68000 based Palms?||http://www.climov.com/zaurus/qpose/|
|x86/DOS||Bochs||very slow, create a bochs image on a PC first then copy to Zaurus||http://bochs.sourceforge.net/ - zaurus port at http://www.its.caltech.edu/~tzer-jen/zbochs/|
|x86 virtual machine||qemu||very slow, create a qemu disk image on a PC first then copy to Zaurus||http://fabrice.bellard.free.fr/qemu/|
|PSX||ZPSX||currently in active development, see http://www.oesf.org/forums/index.php?showtopic=17052|
-- unfinished, but hopefully experts will add stuff.