Its not an insurmountable problem, becasue a generic UI
library would most
likely me somewwhat like libvstgui, which defines an API that pligins use
to provide controls (in theory). There is an implemntation of libvstgui
for IRIX + X Windows, targeted against Motif. Its 'just' a case of
implemting the API in your hosts toolkit and providing that to the plugin.
you still need one per-possible-host-toolkit, though :)
--p