Launcher is a tool which is required to run the more recent titles. It sets up the AVS environment for the target game to boot before it runs the it.
Typically, the tool is run when you use one of the bat script files to start any of the games that require its usage, e.g. newer IIDX games.
It comes with option switches to configure the AVS environment and for development, e.g. Halting until a debugger is attached, outputting debug output to a logfile etc. Just run the application without any parameters to get a usage message:
launcher.exe