I am currently porting The Synthesis ToolKit in C++ to ActionScript (not using Alchemy…). At this moment, 5 instruments are ported and >10 more is coming.
The performance is not yet optimized so real-time sound generation is not ready, and I don’t know if AS3 is fast enough to do that… Anyway here below a early demo generates the ByteArray first and feeds it to the sound during playback.
Updated 2009-09-19: More instruments are ported and added to the demo.
Note that every element’s loudness is different, adjust your speaker so that your ears wouldn’t hurt :)
Download link can be found in STK in AS3 in Google Code.