Piano patches programmed for early digital samplers are often satisfying to play and hear. Some quality that those patches possessed was usually lost as piano emulations became more sophisticated. Pianofax is a low-fidelity piano sample playback instrument seeking this aura.
The samples are fed into basic digital resonators that emulate, after a fashion, the sympathetic resonance of an acoustic piano. This instrument tracks sustain pedal MIDI messages. If you don’t have a pedal, use the ‘Manual Sustain’ switch in the GUI.