Audio Damage has released Rough Rider Pro - a more advanced version of its free Rough Rider compressor.
Designed for extreme compression (it offers ratios up to 1000:1), Rough Rider Pro has three bands and gives you full control of each. An extremely short attack time enables the creation of distortion effects, and there are multiple routings.
An Isolator section, meanwhile, is designed to give you simple control of input frequencies.
Rough Rider Pro is Mac- and PC-compatible and supports the VST and AU plug-in formats. If you're using the VST version, there's MIDI learn for all parameters.
The price is $49.