Variants of DOS 3.3?

[Lyrical Nanoha <LyricalNanoha@dosius.net>]

System disks for AmDOS, David-DOS, ProntoDOS and DiversiDOS have shown up 
on Asimov, so I know where they come from, but I've never seen similar for 
other DOS 3.3 variants.  Does anyone know where, more specifically, some 
of the others originated, like UniDOS, ESDOS ][ and ZDOS 2.2?

btw I have somewhere a hack that has ZDOS's unusual habit of doing a 
GR:TEXT:HOME before displaying the prompt, but doesn't click like ZDOS.

Also I have seen a couple different versions that are verbose when RWTS is 
called, and some that hide the ] that appears when you boot DOS 3.3 (but 
just run a normal program, sometimes even Applesoft).

-uso.