Tcl - the reason for most of the commotion on this Wiki! What is Tcl?
Tcl stands for Tool Command Language - but is not typically thought of as an acronym (and pronounced like "tickle" by all in the know).
There are so many URLs that could be placed here - hopefully the important ones make it:
http://purl.org/tcl/home/ , http://www.tcl.tk/ , and http://www.tcl-tk.net/ point to the same major web site containing lots of information regarding Tcl.
This wiki is yet another.
http://purl.org/net/tcl-faq/ is a series of pointers to other documents.
http://sf.net/projects/tcl/ is the home for the source code of Tcl. At this web site is not only the Tcl releases, but also the thread extension and currently some MacOS X snapshots. The CVS also shows the sample TEA extension code residing in this project - unfortunately, it does not yet appear that this code has been released as a package.
Binary Distributions and places to find Tcl binaries and sources are two pages to discuss locating Tcl binaries.