https://app.karst.systems/

Building instruments in Karst is now FREE — open your desktop browser (Chrome is best) and start patching. This update also ships 11 new instruments, a snappier UI and a pile of under-the-hood work.
Karst is a digital modular for composing with systems — combine instruments & FX into interactive music systems, play them with global macro controls, roll the dice for variations on the scenes you’ve built up, and (soon) share them with the world.

Building is free: make your own instruments in the node editor, in the browser, forever
11 new instruments & boxes: Eucloid sequencer, Flexstep, 2-Op FM synth (with gloriously unhinged FM feedback), Kick / Snare / Hat engines, Mod Filter, Mod Delay, Sidechain Pump, Bouncer (bouncing-ball trigger processor) and Subdivide (the first transport processor)
New systems to play — and fork, if you’re a backer: Bucky Ball, Two Operators and four examples showing how you can use the new instruments I’ve built
Refactors, bug fixes and data-safety work throughout

Got an idea for an instrument, effect, sequencer or trigger processor? Leave a comment! I don’t want Karst to only sound like me. I’ll have a crack at building the best suggestions.

The hat engine’s Karplus-Strong physical modelling is inspired by Zion Jaymes’s brilliant drum-modelling videos — go check out his channel.