SKnote has released the Stereo Double Compressor, otherwise known as SDC. On each channel you'll find an optical compressor followed by a discrete VCA compressor; the first device is designed to control the average signal level, while the second is there to control peaks and add some snap.
You can choose from three optical models and three transformer models, while a Mid/Side encoding and decoding matrix is on offer, too. There are also several metering options.
Said to be useful for both mixing and mastering, SDC is available now from the SKnote website. The introductory price is $29.99, and it's compatible with PC and Mac in 32/64-bit VST/AU formats.