VST MIDI Control Extension (MCX) is a plugin wrapper attached to the selected VST plugin that extends the plugin with MIDI controlling capabilities. The extension allows you to assign each parameter of the VST plugin to a MIDI Controller (CC0 - CC127). It works with both VST and VSTi plugins. On VST hosts without or with bad MIDI controlling setup, you will be able to control your virtual devices from your MIDI controller very easily.