John Ousterhout is the original force behind Tcl and Tk. See http://purl.org/tcl/home/scripting/tclHistory.html for John's recounting of Tcl's early days. (2001-05-14) JO's homepage is now at http://home.pacbell.net/ouster/
See An Overview of Tcl and Tk, Writing Tcl-Based Applications in C, Building User Interfaces with Tcl and Tk, and An Introduction to Tcl Scripting, which are based on a series of powerpoint slides John used for tutorials. The original slides, plus postscript versions, can be found at ftp://ftp.scriptics.com/pub/tcl/doc/tut.tar.Z .
His recent writings in the TclCore mailing list can be seen at http://aspn.activestate.com/ASPN/Mail/Browse/ByAuthor/[email protected]