Ah. Debian.
In theory, since it has an ARM port, you could use it on the Z (I'm actually thinking of looking into it).
There is PocketWorkstation (
http://pocketworkstation.org/), which is Debian for the Zaurus, but it's not the latest version. You could look into that. There are how-tos on the forums here.
If you want to run "desktop PC" apps, take a look at pdaXrom or PdaXii13. They are very similar to "normal" Linux.