Reaktor now actually is almost 10 years old; used to be called Generator. (I worked at Native Instruments before founding Directed Edge.) Similar to Reaktor i

Reaktor now actually is almost 10 years old; used to be called Generator. (I worked at Native Instruments before founding Directed Edge.) Similar to Reaktor is also Max/MSP and its uglier, but open source, cousins jMax and Pd. For things a little closer to code there are CSound and SuperCollider and the less-mature-but-more-elegant ChucK.