OT: DVD Authoring

Anyone know of a good DVD authoring program for Mac, Linux, or even
Winblows? Apple has DVD Studio Pro *drools*, but I don't have the
equipment for that. Suggestions? I seem to recall a couple small ones
for linux with references to k3b, but I need, at the very least, menu
design/layout and would really like encoding too. Think pro quality.
Thanks,
Bryce