About
What this is
altstrument is a directory of custom and third-party firmware and tools for music hardware. Entries are grouped by device and then by firmware project. Each one records the authors, where the source lives, the license, and the version history, so you can tell who made something, whether you can read it, and how recently it was touched.
Scope
The catalog covers grooveboxes, synths, samplers, drum machines, controllers, pedals, Eurorack modules, vintage gear, and DIY platforms. Host-side tools that support a scene, such as editors, flashers, emulators and SDKs, are listed alongside the firmware they serve.
Policy
We link; we never host firmware binaries. We also never link to redistributed copies of manufacturer firmware. Where a project works by patching a stock file, you supply that file yourself from the manufacturer.
Entries carrying a brick-risk flag have a known, documented risk of damaging the device. Flashing third-party firmware may void your warranty, and doing so is at your own risk. Read the project's own notes before you start, and keep a way back to stock where one exists.
Reading the badges
Status describes how alive the project is.
- Active
- Commits or releases within roughly the last year.
- Maintained
- Stable, with infrequent updates; the author is still responsive.
- Dormant
- No activity for a long time, but still usable.
- Archived
- Explicitly archived or abandoned by the author.
- Announced
- Publicly announced, with nothing downloadable yet.
- Unknown
- Project state has not been established.
Source describes how much of the work is public.
- Source: open
- Full source is published.
- Source: patcher only
- The patch tooling is public; the firmware changes themselves are not.
- Source: binary only
- Only compiled images are distributed.
- Source: closed
- Nothing is public.
License is an SPDX identifier linking to the license text. Two values are not licenses in that sense and appear as plain, muted badges.
- proprietary
- All rights reserved, or custom non-open terms.
- unspecified
- No license file or statement was found.
Contributing
The catalog is plain YAML. To add or correct an entry, open a pull request that adds or edits a file undersrc/content: one file per device in devices/, and one per firmware project infirmwares/<device>/. A validator checks the schema on every build. SeeCONTRIBUTING.md in the repository for the field reference and the rules about omitting dates rather than guessing them.
Prior art and thanks
This site builds on lists others have kept for years:
Lapin/awesome-music-gear-firmwarearoum/fm1-custom-fwMaxhodges/noise-engineering-firmware-index- Mutable Instruments' third-party firmware page
Licensing
The site code is released under the MIT license. The catalog data is released underCC-BY-4.0; reuse it with attribution. A full JSON export is available at /api/catalog.json.
Device images are the manufacturers' own product and press photos, shown with attribution and a link to where they are published. They remain the property of their owners and are not covered by the catalog's CC-BY-4.0 license. Where no product image is available, the manufacturer's logo is shown instead; those are public-domain wordmarks or brand assets used with permission, and remain trademarks of their owners. If you own an image or mark shown here and want it changed or removed, open an issue.