The Tcl Windows API (TWAPI) extension provides Tcl bindings to a subset of the Windows API.
The extension provides access to the Windows API at two levels. A direct interface to the supported Windows API is provided where the Tcl commands directly map to Windows functions as described in Microsoft Windows SDK. The recommended interface is a higher level interface that is more convenient, powerful and much easier to use than the raw Windows API.
TWAPI is open source with a BSD license.