I just stumbled upon LabView: http://en.wikipedia.org/wiki/LabVIEW#Dataflow_programming It is not specific to audio but has a stream/flow-oriented programming language. The language can be used graphically. Each component (they call them Vitural Instruments, we call them sources) bundles three things: a block diagram (the behaviour), a connector pane (the possibility to plug inputs/outputs) but also a front panel. The latter aspect is what we haven't developped yet: it's the interactive user interface of the node. That'll probably be useless as most other comparisons, but just in case... -- David
