Edit mode — Put menu (or Ctrl+1/2/3) adds boxes, drag from an outlet to an inlet to connect, Ctrl+E locks the patch, Run compiles it. No undo yet — save often.

Engine: WebPd by Sébastien Piquemal & contributors, compiling patches to JavaScript DSP · free software, LGPL-3.0 · source · Pure Data is by Miller Puckette & community · WebPd is alpha: only a subset of Pd objects is supported (list)