Wikipedia
Pianoteq
Pianoteq is a software synthesizer that features real-time MIDI-control of digital physically modeled pianos and related instruments, including electric piano, harpsichord, fortepiano, and various metallophones. It is usable as a stand-alone program for Microsoft Windows, Mac OS X and Linux platforms, or as a plug in for VSTi hosts and two VSTi counterpart for use with digital audio workstations.