Different Linux distros:
Debian - http://www.internettablettalk.com/wi...p?title=Debian
Poky Linux - http://www.pokylinux.org/getit/
Mamona - http://dev.openbossa.org/trac/mamona/

Different desktop environments:
xfce - http://www.internettablettalk.com/fo...highlight=xfce
kde - http://www.internettablettalk.com/fo...splay.php?f=33

Different OSes: none known.

Emulators:
Palm - garnetvm (and pose)
Dos/Windows(3|9x) - dosbox
Generic x86 - bochs
NES - fceu
Amiga - uae
SNES - snes9x
68k Mac - BasiliskII

If I don't provide a link for it, try searching the forums here.

Post anything else you know about below and I'll add it to this post.

Can we get this stickied, BTW?