SynthMaker 1.0 (173)

Start from code. In the Patch, + › Module of your own › Start from code adds a filter written in five lines. It's one box in the Patch, named by its code, with its own knobs.

Go inside. Open it to see its code or its graph (multiply, add, π, and y' for one sample ago), or both side by side. Type to change it; a pause applies it as one undo step, and a line with a mistake turns red while the sound keeps the last version that worked. Click a part of the graph to find its code, and the cursor in the code lights its part of the graph.

As deep as you like. Modules of your own and the modules you write nest inside each other, and the Code view writes and reads them all, exactly as the web does.