Tcl is a simple-to-learn yet very powerful language. Its syntax is described in just a dozen rules, but it has all the features needed to rapidly create useful programs in almost any field of application - on a wide variety of international platforms.
Tcl, is an acronym for Tool Command Language. The preferred pronunciation is as its individual letters. In the past, the most popular pronunciation was as a homophone for "tickle". The suggested spelling is with an uppercase "T" and "cl".
For many people, their first acquaintance with Tcl is as a component of another software program. Examples include Expect, Cisco IOS
As of Tcl 8.4, the only interpreters that you really need to think about are tclsh, tclkit, and (on some platforms) wish, as Tcl provides the ability to dynamically load any of the other extensions during runtime. In fact, many of the extensions have been dropping the building and installing of custom executables due to this.
Tcl Commands documents all the Tcl commands available in the core distribution.
Tcl C API documents all the public Tcl C calls that a C programmer should consider safe to use.
Tcl also comes with several packages. For instance, the http package, dde, msgcat, platform, registry, tcltest, the deprecated optparse package, as well as others [please fill them in here].
see Why Tcl
See this page for details about platforms known to support Tcl and Tk.
See Getting Tcl/Tk
See Installing tcl
See Documentation
See Learning Tcl
see Tcl Syntax
see Tcl Commands