ruck-ugen's shreduler calculates an audio unit generator
graph's output in virtual time. The graph can be modified by
shreds all the while.
The graph is written in Ruby for flexibility, so it's
too slow (on my computer) for real time, so there is no
real-time playback. You can use WavOut, though.
(See examples/ex01.rb)
Check out the library of built-in unit generators in
lib/ruck/ugen/ugen/ and make your own.
Unit Generator Usage
====================
Play a sine wave (examples/ex02.rb):
  s = SinOsc.new(:freq => 440)
  w = WavOut.new(:filename => "ex02.wav")
  s >> w >> blackhole
  play 3.seconds
Attach lambdas to unit generator attributes
(examples/ex03.rb):
  wav = WavOut.new(:filename => "ex03.wav")
  sin2 = SinOsc.new(:freq => 3)
  sin = SinOsc.new(:freq => L{ sin2.last * 220 + 660 },
                   :gain => L{ 0.5 + sin2.last * 0.5 })
  [sin >> wav, sin2] >> blackhole
  play 3.seconds