Professional Sound Projects has released PSP PianoVerb - a reverb effect for Mac & Windows - as a free download for the holidays:
To celebrate Santa Claus day we are RE releasing our freeware plug-in: PSP PianoVerb which reproduces special kind of reverberation originally provided by piano strings.
PSP PianoVerb generates reverberation using twelve string operators with adjustable damping and decay time. Each of them is tuned to a particular note starting from A(55Hz) to a G#(103.8Hz). The PSP PianoVerb string system can be transposed in the range of +-24 semitones, tuned within a range of +-100 cents and be detuned as well.
Transposing to lower octaves produces a bigger and less resonant sound similar to traditional reverbs, while in turn transposing to higher octaves produces a very bright harp-like effect.
Note:PSP PianoVerb is free, but requires authorization with an account at the PSP site.