I found an interesting synth for my android phone the other day called VirtualANS (
http://en.wikipedia.org/wiki/ANS_synthesizer ). Going to the authors website (
http://warmplace.ru/soft/ans/ ) I realized that it included a linux version including JACK support. It does not include source or nice a nice installer. I have it running acceptably (command line only so far) but was thinking about what would be required to package it nicely for gentoo. Also.. does proaudio have a policy about non-opensource programs? It is based on pixilang (same author) which includes source and is under MIT license.
Matt