Tcl

Tcl (originally from "Tool command language", but nonetheless usually lowercased) is a [scripting language]? that is very easy to learn, with Lisp-like features. It is also famous for its tk? toolkit, that allows one to write portable graphical user interfaces for a variety of [operating systems]?. The combination language plus toolkit, known as tcl/tk, was created by [John Ousterhout]?.

See [Tcl FAQ], [Tcl'ers Wiki], [Tcl Contributed Sources Archive], Programming language.