I have a predilection for SuperCollider. I use it for almost all the music I compose. Here is how you can get my extensions.
The Sponge Object
The PresetInterpolator Object
The PresetInterpolator allows to interpolate smoothly between any number of presets. It was inspired mostly by AudioMulch’s MetaSurface.
It is part of the mmExtensions. You can get these using git (git it directly in your SuperCollider Extensions folder):
git clone git://github.com/marierm/mmExtensions.git
This will also get you the SpongeBee.sc file.