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/viewcvs.py/*checkout*/tomasoft/tes/OSCON2K%2B1_TclTrack.html?content-type=text%2Fhtml