Tcl (Tool Command Language) is a very powerful but easy to learn dynamic
programming language, suitable for a very wide range of uses, including
web and desktop applications, networking, administration, testing and
many more. Open source and business-friendly, Tcl is a mature yet
evolving language that is truly cross platform, easily deployed and
highly extensible.

Tcl/Tk resources:
  Newsgroup: comp.lang.tcl
  Wiki: http://wiki.tcl.tk
  Book: Practical Programming in Tcl and Tk, 4th Edition
        ISBN: 0-13-038560-3

"Routine maintenance of Tcl/Tk 8.4 has now come to an end.  We intend
Tcl/Tk 8.4.19 to be the final 8.4.* releases.  The current stable
releases of Tcl/Tk are 8.5.2, and development has begun on Tcl/Tk 8.6.
It is possible that a bug fix of great enough importance or severity
might prompt a release of 8.4.20, but there is no plan for that at the
moment.  Even that level of support will fade away quickly."
- Tcl/Tk 8.4.19 Release Announcement April 18, 2008