Tcl

Tcl (originally from "Tool Command Language", but nonetheless conventionally rendered as "Tcl" rather than "TCL"; and pronounced like "tickle") is a scripting language created by John Ousterhout that is generally thought to be easy to learn, but powerful in the right hands. It is most commonly used for rapid prototyping, scripted applications, GUIs and testing. Tcl's features include:

• Everything is a command, including language structures.
• Everything can be dynamically redefined and overridden.
• All data types can be manipulated as strings, including code.
• Extremely simple syntactic rules
• Event-driven interface to sockets and files. Time based and user defined events are also possible.
• Dynamic scope
• Readily extensible (with C, C++, Java and Tcl)
• Interpreted language, code can be created and modified dynamically
• Full Unicode support
• Platform independent (Win32, UNIX, Mac, etc.)
• Close integration with windowing (GUI) interface Tk
• Code is easy to maintain. Tcl scripts are often more compact and readable than functionally equivalent code in other languages

While Tcl itself does not provide an object oriented framework, the language itself can be extended to provide new features as required. Indeed, many C extensions have been written to provide OO functionality, including the XOTcl and incr Tcl packages. Other OO extensions, including Snit, are written entirely in Tcl.

The most popular Tcl extension is the Tk toolkit, which provides a graphical user interface library for a variety of operating systems. Another popular extension is