TES is David Gravereaux's Windows-specific Tcl-interpreter-in-C++-application embedding experiment.
He maintains it at http://sourceforge.net/projects/tomasoft/ .
The acronym stands for Tcl Event System.
Read the docs for it @ http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/tomasoft/tes/OSCON2K%2b1_TclTrack.html?rev=1.5&content-type=text/vnd.viewcvs-markup