Strudel is a music live coding environment for the browser, porting the TidalCycles pattern language to JavaScript.

Wavacity is a port of the Audacity audio editor to the web browser. Free and open-source. No install required.

This Mario Paint inspired composer tool is easy and fun. You can create simple and beautiful songs right in your browser and share them with the world!

Official homepage for Little Sound Dj, the ultimate Game Boy music editor.

MuseScore's core library (libmscore) in WebAssembly! Read mscz data, and generate audio/MIDI/MusicXML/SVG/PNG/PDF sheets right in browsers. - LibreScore/webmscore

JummBox is an online tool for sketching and sharing instrumental music.

Cacophony is a minimalist and ergonomic MIDI sequencer. It's minimalist in that it doesn't have a lot of functionality MIDI sequencers have. It's ergonomic in that there is no mouse input and a very clean interface, allowing you to juggle less inputs and avoid awkward mouse motions.

BeepBox is an online tool for sketching and sharing instrumental music.

A browser-based generative music environment based on octave-repeating microtonal tuning systems and their subsets (scales/modes).