Grasso is a complete saturation and dynamics unit.
It is NOT a compressor, no thresholds.
It is NOT an envelope shaper, no triggering.
Is includes some special features like level-independent dynamics, tube-saturation stage, dynamic and level-independent pre-drive filtering, spank control and a modeled power-supply.
It is very useful to add color and dynamic control to mixes and single tracks, from subtle to extreme.
Available as Win32/64 VST, Mac32/64 VST/AU