An audio plugin host
Carla is a fully-featured audio plugin host, with support for many audio drivers and plugin formats.
It's open source and licensed under the GNU General Public License, version 2 or later.
LADSPA, DSSI, LV2 and VST plugin formats
SF2/3 and SFZ sound banks
Internal audio and midi file player
Automation of plugin parameters via MIDI CC
Remote control over OSC
Rack and Patchbay processing modes, plus Single and Multi-Client if using JACK
Native audio drivers (ALSA, DirectSound, CoreAudio, etc) and JACK
In experimental phase / work in progress:
Export any Carla loadable plugin or sound bank as an LV2 plugin
Plugin bridge support (such as running 32bit plugins on a 64bit Carla, or Windows plugins on Linux)
Run JACK applications as audio plugins
Transport controls, sync with JACK Transport or Ableton Link
Carla is also available as an LV2 plugin for MacOS and Linux, and VST plugin for Linux.