There are a dizain of scripting languages, Tcl/Tk is just the prefered one here :

• Multipurpose swiss knife : networking, databases, graphical apps, …
• Used by the largest companies in any field : NASA, Cisco, Motorola, Synopsys, …
• Excellent portability
• Graphical tools
• Users of excellence
• Many Open Source tools and extensions
• Easy to learn, easy to install
• … well just a Premier language !

Tcl/Tk is said to be the best secret of the internet, probably because it can manipulate regular expression, interface easily with large applications : AOL, Oracle, FEA softwares, at a light cost cost of programming. But there also Tcl applications with thousands lines of code. Some utilities or very useful applications are :

• Visual Tcl (SourceForge)
• BLT, IncrTcl and IWidgets
• Ramdebugger
• Ased
• TclPro (SourceForge) or Tcl Dev Kit (ActiveState)
• Mk4Tcl (Equi4)
• TkDiff
• … and dizains of others

Where to start ?

• If you are an experienced scripter or want to convince any one around just go to
  www.tcl.tk/about

• If you are new to Tcl/Tk first go to
  tcl.activestate.com/doc

• You will find an excellent support , here :
  groups.google.com/group/comp.lang.tcl/topics (en)

• And to know everything :
  
  Wikipedia
  en.wikipedia.org/wiki/Tcl (en)
  Wiki
  wiki.tcl.tk (en)

History

John K.Ousterhout started it in Berkeley University in Fall 1987. Then was Tcl/Tk was ported on Windows … in Sun Labs, concurrently with the development next door of Java. After two startups, Tcl/Tk is now supported by ActiveState

Internet allows Tcl/Tk to grow around many applications mainly in networks. Java, Perl, and Php since then are found in more applications. Anyway for new developments, Tcl/Tk stands to be an efficient solution : portable, compact and reliable.

For the people knowing French, the best book (according to us !)is Bernard Desgraupes's book (Editor : Vuibert). It is consistent, pratical, and is based on the version 8.4 of Tcl/Tk.

Because its first purpose is to be a gluing language based on C with a strong portability all technology domains use it :

• EDA software
• Biology
• Space
• Geography
• Data Processing
• …