Windsor

A browser-based sequencer and DAW built on a custom four-operator FM engine:

• Synthesis: FM, harmonic waveforms and subtractive filtering in AudioWorklets.
• Sequencers: Euclidean, grid, chord, arpeggiator, bass/drone and figure, driven by a harmony timeline, and a piano roll whose notes keep their pitch. Bounce to Roll turns a generated part into notes you can edit.
• Mixer: channel strips with up to eight inserts each (compressor, classic and advanced drive, tape, filter, parametric EQ, chorus, ensemble, phaser, dub delay, echo, plate and retro reverbs, and bloom, a harmonic pad generator), two send buses with their own insert chains, and a song master. Song automation lanes move the knobs over time.

Everything runs in the browser, and the app deploys as static files. Try it at https://tacowars.github.io/windsor/. Chrome is the tested browser.

Windsor began as the audio engine for a web-based game I was building, but I soon became more interested in the synthesizer and sequencer than in the game itself, so I forked it and Windsor was born. The synth takes its influences from some of my favourites, like the Korg opsix and Ableton Live's Operator. The sequencer draws on many sources, but I want to call out Plugin Boutique's Scaler and Elektron as general influences.

The plate reverb is based on the Dattorro algorithm, which is my favourite, and I think it pairs well with the harmonically rich sounds the synth can make. If you enjoy Windsor, let me know.

The name comes from Windsor, Ontario, where kids grew up listening to radio broadcasts by the seminal techno artists from Detroit. Windsor can be used to make any kind of electronic music, but the techno mentality is at the heart of its design: step sequencing, polymeter, groove, acid and rhythm.

Getting started

nvm use            # Node 24
npm ci
npm run dev        # http://localhost:5173

Click Enable audio, pick a sequencer for Part 1 and press ▶. Audition with the QWERTY keys, the on-screen keyboard or a MIDI controller.

Building and deploying

npm run build      # writes packages/app/dist/
npm run preview    # serves it locally

packages/app/dist/ is a plain static site: HTML, the hashed app bundle and one file per DSP worklet. Serve it from any static host over http(s); worklets don't load from file://. The build uses a relative base, so it works under a sub-path such as a GitHub Pages project site. Set WINDSOR_BASE to override it.

CI (.github/workflows/ci.yml) runs npm run verify on every pull request and every push to main. GitHub Pages serves the gh-pages branch:

• Live: a push to main that passes publishes the build to the branch root, https://tacowars.github.io/windsor/.
• Previews: a pull request from this repo that touches code publishes its build to https://tacowars.github.io/windsor/pr-preview/pr-<N>/ and comments the link on the PR. Closing or merging removes it.

Repository layout

• packages/engine/: @windsor/engine, the audio engine and its patch library.
• packages/app/: @windsor/app, the browser UI, plus the patch-library scripts.
• scripts/: the worklet bundler and the patch-library index.
• docs/: the design docs, decision records and research.

npm run verify is the gate every change passes. CLAUDE.md holds the engineering rules.

Licence

GNU Affero General Public License v3.0.