The sfz format is simple, minimalistic, expandable and free, you can find out more at rgc:audio's sfz format page.
Some of the features of the sfz format are:
- Samples of any bit depth (8/16/24/32-bit) support, mono or stereo (.WAV & .OGG).
- Samples taken at any samplerate (i.e. 44.1k, 48k, 88.2k, 96k, 176.4k, 192k, 384k).
- Compressed samples. Compressed and uncompressed can be combined.
- Looped samples.
- Unlimited keyboard splits and layers.
- Unlimited velocity splits and layers.
- Unlimited regions of sample playback based on MIDI controllers (continuous controllers, pitch bend, channel and polyphonic aftertouch, keyboard switches) and internal generators (random, sequence counters).
- Sample playback on MIDI control events.
- Unlimited unidirectional and bidirectional exclusive regions (mute groups).
- Unlimited release trigger regions with release trigger attenuation control.
- Unlimited crossfade controls.
- Trigger on first-note and legato notes.
- Sample playback synchronized to host tempo.
- Dedicated Envelope Generators for pitch, filter and amplifier.
- Dedicated LFO for pitch, filter and amplifier.