Tcl
From Just Solve the File Format Problem
Tcl (Tool Command Language) is a scripting language dating back to the 1980s. Although its name is an acronym, its promoters prefer to spell it as a word (with only an initial capital), and it's sometimes pronounced "tickle". When combined with the Tk GUI toolkit, it's "Tcl/Tk".
The main use of Tcl is as an embedded scripting language within larger software packages, rather than as a standalone programming languages. It gained some popularity for this use until later losing ground to the whole profusion of scripting languages (e.g., Perl, Python, PHP, Ruby, JavaScript, Lua, etc.) which sprung up in the years following its introduction.