jsCompShaper is a free compressor VST plugin released by Johannes S. Mueller-Roemer and Nick Moritz.
Yet another compressor, but this one has the ability to morph between soft-knee compression and waveshaping as desired. Furthermore, it provides pre-/post-emphasis filtering (similar to a side-chain filter) and a more analog-like attack than jsComp (see below).
The GUI was designed by Nick Moritz (RADO Records).
This useful compressor plugin comes with 36 pre-built presets and it is totally free for any use including commercial releases.