These days, UMAX just makes various scanners and a few related products. Previously, however, they made many PowerPC machines (they were quite popular in Europe, I believe). Sitting right next to me on the table is a 200 Mhz PowerPC 604e which is marked as a UMAX processor, in fact.
I seem to recall that they also made x86 workstations a few years ago, some of which seemed quite nice. I can't find any information about these now, I just remember seeing ads in Computer Shopper and the like.
I think it's quite unfortunate that nobody is in the desktop PowerPC business nowadays except Apple (Motorola and IBM are mostly doing embedded and server machines). While Apple's G4 Tower is exceptionally nice (I used to have a dual 800 Mhz G4 as my workstation at JHU), it is far too expensive to really consider buying (at least on my current budget).