UBBdev.com is the official site for unofficial UBB modifications
It used to be very active, but seems to have slowed down since Threads 7 replaced earlier products. :/ But it's still the place to ask for/get custom mods (such as a spell-checker) that aren't currently featured in the standard software...
(Okay,
again glider posts right before me! Maybe I'll just get to some other work then...
)