Carla is a fully-featured modular audio plugin host, with support for many audio drivers and plugin formats.
It has some nice features like transport control, automation of parameters via MIDI CC and remote control over OSC.

Carla currently supports LADSPA (including LRDF), DSSI, LV2, VST2, VST3 and AU plugin formats, plus SF2 and SFZ file support.
It uses JACK as the default and preferred audio driver but also supports native drivers like ALSA, DirectSound or CoreAudio.

There are 4 types of engine processing:

• Single-client: (JACK driver only)
  Same as Multi-client, except that all JACK ports belong to a single master client.
  This is needed when a setup doesn’t support multi-client JACK apps, such as LADISH.
• Multi-client: (JACK driver only)
  Setiap pemalam tunggal didedahkan sebagai pelanggan JACK baharu. Port audio dan MIDI didaftarkan mengikut keperluan.
• rak:
  Pemalam diproses mengikut urutan, dari atas ke bawah.
  Pemalam dengan saluran audio bukan stereo tidak disokong, tetapi pilihan stereo paksa tersedia untuk yang Mono.
• Patchbay:
  Mod patchbay modular, sama seperti dalam JACK Multi-client dan banyak aplikasi modular lain.
  Setiap pemalam mendapat kumpulan dan port kanvas tersendiri yang membolehkan anda menyambung audio pemalam dan MIDI.