So, I'm wondering... I don't image that the external Ugens have been fixed yet, have they? If not, would you be interested in taking a patch that re-enables them? My own personal burning desire: support for VST in chuck. My personal feeling about chuck right now: the fixed list of audio-rate ugens is constraining, wonderful as STK is. Chuck sequencing and precision in conjunction with commercial-grade VSTs would be a killer combination. And to that end, I'm willing to contribute some effort to bring up the external ugens. For licensing reasons, you wouldn't want VSTs to be internally implemented, I think, because you'd pick up the Steinberg licensing requirements. Pieces of work that I'd see as being necessary. (I've reviewed the relevant sources in about the 1.2.0.4 timeframe, and I'm guessing that the general gist of the sources remains the same). - Rework the audio processing spine to allow for block processing of audio between successive events. (One sample at a time incurrs a massive performance hit when interacting with VSTs: 10x + in common cases, and the same would be true of external ugens, generally. The alternative would be buffering, but I'd like to push for gold). The general idea: circular dependencies in the audio-rate connections would cause a fall-back to sample-at-a-time processing; non-circular references would allow a mixture of block-based and sample-based processing. - Resurrect and re-enable the external ugen code. It appears to be mostly there, and probably fixable, but missing access from the language itself. I can provide coverage and test cases for for Win32/Visual studio and cygwin/g++ compiles. - Publish an opensource implementation of an external VST ugen. That's a fairly modest bundle of work, but will touch a passel of core files. How stable are the core sources right now? If I take a week or two to do this what are my chances of facing a merge nightmare once I'm done? Is now a good time to do this kind of thing? Are you interested? Is this more of a help than a hindrance at the present time?