I can already hear the screams from the rafters telling me how terrible of a choice Python is - but in my case, I valued modularity, extensibility, hackability over raw performance. (It was also a challenge to myself to see how far I can get without referencing existing implementations)

Synchrotron processes nodes: simple Python classes with typed I/O and a render() method for processing. It can be as concise as 5 lines:

    class IncrementNode(Node):
        input: StreamInput
        output: StreamOutput

        def render(self, ctx):
            self.out.write(self.a.read(ctx) + 1)

Currently you can build synths, FX chains, MIDI instruments, arpeggiators, controllers, or just mess about with sound :>

Editor: https://synchrotron.thatother.dev/ Source: https://github.com/ThatOtherAndrew/Synchrotron

It's still experimental (and my first ever shipped project), but I'd love feedback from people who tinker with audio/DSP/live coding. Docs are terrible currently, but that's my next big goal!