What is Playa!TraX? What does it do?

Here is an example -- Playa!TraX is running idle in the system tray. You launch a full screen game, Half-Life 2 for example, Playa!TraX on its own will start playing your Half-Life 2 playlists and load a configuration that allows you to control the music (through any input device) without having to see the player. Playa!TraX also has a in game on screen display and optional voice control.