A fully free and self-contained modular synthesizer
based on the popular VCV Rack

Available in AudioUnit/CLAP/LV2/VST2/VST3 plugin formats and as a standalone app for FreeBSD, Linux, macOS, Windows and the Web.


Created first and foremost as a way to have Rack as a conventional open-source audio plugin.


Cardinal does not load any external modules, everything is built-in.

LV2 support

Supporting real CV ports to and from the plugin, for integration with other modular systems.


Supporting more than just the basic 3 desktop operating systems.

1219 included modules

A total of 1219 modules from 79 different authors/brands.

3 Plugin variants

A "main" variant plus Synth and FX.

Get involved

Development happens on GitHub and we chat on the #cardinal IRC room in irc.libera.chat server.
Come join us in your favorite IRC client or through your web browser (no post history).