OpenKinect is a project mainly written in ..., it's free.
OpenKinect
OpenKinect project
Copyright (c) 2010 Joshua Blake and other contributors
The folder INF contains Windows drivers. Plug in Kinect and during the driver installation browse to the proper folder. The drivers were generated via libusbdotnet tools and are distributed under their own licenses.
The rest of the project is distributed under the Apache 2 license.