Waldorf Largo - softsynth with typical Waldorf sound, up to 256 voices per instance (depending on available CPU power), up to 4 layers per sound, host automation of almost all parameters, MIDI controller automation of the most important parameters, flexible arpeggiator with 16 freely programmable steps, effects: chorus, flanger, phaser, overdrive, delay and reverb. Compatible with Windows XP and Mac OS X, requires Steinberg Key 178823