Noisebud makes Midsider 1.0 Free for Windows
Noisebud has made their plugin Midsider 1.0 available for free. Midsider will give any VST plugin mid/side abilities.
Version 1.0 was built to be used in REAPER but can work in other DAWs as long it can handle more than 2 audio channels per track.
The upcoming version 2.0 will work in any DAW and will also be available for OS X.