WIDI VST Plugin is compatible with many application supporting VST Plugins.
To use WIDI VST Plugin, you need to set up an Audio Track and a MIDI Track. The VST should be connected so it gets data from the Audio Track and writes data to the MIDI Track.
Unfortunately, some VST hosts cannot accept MIDI data from the plugin (even if they can process it themselves), see routing MIDI for details.
Generic procedure of setting up WIDI VST Plugin
Open the VST Host application and load Audio data into it.
Add WIDI VST Plugin to the output of an Audio Track or Audio Player. It may require first adding the Plugin to the workspace and then connecting its input to the Audio Track output.
Create a MIDI track if possible. Attach WIDI VST Plugin output to the input of the track.
If no tracks can be created, try to attach the plugin output to the general MIDI input or bus of the VST host.
If this attempt also fails, it is most likely your host does not support getting MIDI data from VST. Try output to the MIDI Out Device (see routing MIDI for details) or record MIDI to the MIDI file with a built-in MIDI recorder.