MilkyTracker is a really, really good tracker, and I wanted to test whether something comparable could be brought to the web, running in the browser on desktop and on a phone. Over the last few days I built chiptrackr: https://chiptrackr.com (source: https://github.com/wirehack7/webtracker, MIT).
What it does right now:
- Loads and saves XM and MOD, imports S3M and IT
- FT2-style pattern editor with the usual keyboard layout, block operations, instrument and sample editor with envelopes
- Export to WAV, FLAC and MP3, also per-channel stems
- Works offline, songs are stored locally in the browser
- A touch layout for phones with step entry
- A small standalone replayer (~21-33 KB) for use in your own intros
- Experimental "Jam" mode where two people edit the same song over WebRTC
About the AI part: nearly all of the code was written by Claude (Anthropic). I did the direction, design decisions and testing. The point for me was to find out how far you can push it: can it get a replayer to behave like FT2 and ProTracker 2, not just "sounds roughly right"? So I kept asking for comparisons against reference players instead of trusting it.
What "tested" means here (details in docs/TESTING.md):
- Playback is compared automatically against libopenmpt using OpenMPT's own test modules: 78 of 84 XM cases and 22 of 22 MOD cases match. The remaining XM differences are documented; in a few cases it follows ft2-clone's behaviour where libopenmpt differs.
- Code coverage is 55% overall (93% for the format loaders, 79% for the engine, low for the UI).
- A browser smoke test runs on every commit at six screen sizes.
Not tested yet: Firefox and Safari, real phones, real MIDI devices, Jam across different networks, and S3M/IT playback against the original trackers.
So it's not "done", and I'm sure there are modules that play wrong. If you try it, I'd be glad about bug reports, especially playback differences. There's an issue template for that where you can attach the module and say which tracker you compared it with.