divVerent wrote: so one should play as safe as possible.
Not live one's life on the knife's edge of oblivion? Comon man, life ends at 30, live fast die hard!
If a fully opensource synth is needed zynaddsubfx can be used and, in addition to all the instruments it does have allready, these gpl ones can be added: http://www.musically.me.uk/stuff.html (the ZynBank). ZynAddSubFX is available in most linux distributions and windows etc.
http://zynaddsubfx.sourceforge.net/
"Synthesizer with two engines, realtime polyphonic, Midi support, microtonal capability, effects."