Max/MSP is a 'data flow' programing environment used for building multi-media applications that control sound, video or 3D graphics. Chunks of code are represented on the screen as objects, joined by chords to form a sort of flow-diagram that actually functions. The Max part can be used to create complex Midi functionality, and MSP can be used to build software sampler sequencers, synthesizers and so fourth. Max/MSP grew out of a program called Pd (Pure Data), which is still available as an open source version of the data flow programing idea.