Hi Brett,
I use Linux for most of my work, and for all my lilypond work.
What are you trying to establish, may I ask? A statistical survey of platform usage? Or are you really asking about what graphical tools are available? Your query seems to have multiple aspects.
The Linux platform is strongly supported by the lilypond developers.
I seem to rememver there was some sort of usage survey on the list a couple of years ago.
Andrew