apulSoft has ported Slim Slow Slider's Side Chain Compressor to Mac OS X in VST and AU formats.
Side Chain Compressor is a Side Chain only compressor which requires special routing. For VST there are two versions, mono (2 input channels/1 output channel) and stereo (4 input channels/2 output channels). Not all VST hosts support the required routing - Cubase Studio for instance does not. The AU version uses the regular AU sidechain mechanism and detects mono vs. stereo processing.
WARNING: There have been reports of very loud noises in Cubase 4 with a beta version of this plugin. The routing has not been not very well tested in general. Please use this with care.
