M-VAVE
Works with this editor Latest V15
The firmware every FM1 ships with: a six-operator FM engine compatible with DX7 voices, four banks of 32 presets, effects, an arpeggiator, and a sequencer. Install it with M-VAVE's M-UPGRADE tool, which is also the way back from Felucca and SLOOP.
Baud Girl
Works with this editor Latest FM-1_096
Keeps M-VAVE's FM engine and effects, fixes its engine bugs, and adds a Virtual Analog engine, an 8-Bit engine, a Bitcrush effect, and a 64-step sequencer. It installs from Baud Girl's own browser page, keeps your presets, and can put M-VAVE's firmware back. This editor reads and writes its FM and Virtual Analog presets, effects included, but not its 8-Bit presets yet, which it leaves as they are on the FM1.
Quixotic7
Not supported by this editorBeta · Latest 0.13
A chord instrument inspired by Telepathic Instruments' Orchid: one hand plays roots while the other shapes chords, with voicings, key and performance modes, a bass line, and a looper. Built on Felucca's engines and the monome grid ChoralRoot, it installs from its own browser page and can be tried first in a browser emulator.
Hügelton Instruments
Not supported by this editorLatest 1.0.5.2
Turns the FM1 into a multi-engine synth: thirteen engines, from analogue, six-operator FM, and phase distortion to samples, granular, drums, and physical models from Mutable Instruments' Plaits and Rings, across four tracks with a 64-step sequencer, arpeggiator, and modulation matrix. It has its own web editor and installer, and a browser emulator to try first.
Keitark
Not supported by this editorExperimental · Source only
Plays NES games on the FM1: its 27 keys are the controller and its screen the television. It is the worked example in a kit for writing FM1 firmware from scratch, published as source with no installer page or ready-made release, and no game included. It makes no music.
hericdk
Not supported by this editorNot yet tried on an FM1 · Build 15
SLOOP as a pixel-art RPG. The four tracks are four heroes, every lit step is an attack, the tempo sets how fast the party walks, the key picks the biome, effects bring the weather, and recording a loop is a boss fight against the King Slime. Every SLOOP function stays where it was, with the same controls. It installs from its own browser page, and SLOOP's own release installs over it.
Charles Vestal
Not supported by this editorLatest 0.3
A chord harp inspired by the Suzuki Omnichord: the 16 white keys are the strum plate and the 11 black keys pick the chord, with rhythm patterns, an auto bass, and its own effects. It installs from its own browser page, which can also put M-VAVE's firmware back.
Peter Gombos
Not supported by this editorPaid · Latest 1.1
An eight-track groovebox that keeps an FM synth and adds a virtual analogue synth and drum kits, with a 64-step sequencer with parameter locks, a six-effect mixer, and a performance mode with scenes. It installs from its own browser page, which can also put M-VAVE's V15 back, and has a browser emulator to try first.
zednaked
Not supported by this editorAlpha · Latest 0.5.1
A Felucca fork with a dark, industrial, and Brazilian accent: ten engines, among them a six-operator FM and a superwave analogue, four tracks, a modulation matrix, ratchets, drones that hold and evolve while you play, and drum kits of its own. It installs from its own browser page, and Jangada Studio plays its sound in a browser.
ip2k
Not supported by this editorNot installable yet
Open firmware in the making, with engines derived from Mutable Instruments' modules and a Movy-style sequencer. For now it runs only as a virtual FM1 in a browser: it cannot be installed on an FM1 yet, and has never written anything to one.
keremimo
Not supported by this editorLatest 0.11.1
A Felucca fork that follows Felucca 1.0's design and adds engines of its own, among them CZ-1, which plays Casio CZ-1 tones, with all 64 of Casio's preset tones, and takes Casio's SysEx. It installs from its own browser page, which saves a backup first and can return the FM1 to M-VAVE's V15, and it has its own web editor.
isod89
Not supported by this editorBeta · Latest 2.3
A groovebox firmware built on Felucca, with projects, patterns, and songs, and its own web editor for presets and a sound library. It installs from its own browser page and leaves through M-VAVE's M-UPGRADE, as Felucca does.
zvenson
Not supported by this editorBeta · Latest 2.6
SLOOP's live workflow with a DX7 inside: a fork of SLOOP that replaces its engines with one six-operator DX7 engine, ported from Dexed, with every voice parameter editable on the FM1 and room for 256 voices from your own banks. Its drum track plays FM drums you program on the device, and patterns run up to 128 steps. It installs from its own browser page and has its own web editor.
Charles Vestal
Not supported by this editorBeta · Latest 0.10.1
A groovebox in the spirit of ReBirth: a 909, an 808, two 303s with an acid line generator, and a breakbeat player, all playing at once, with automation, shared reverb and tape delay sends, and a master compressor. A fork of Felucca, it installs from its own browser page, which can also put M-VAVE's firmware back.