An E''''''xtensionProgrammingLanguage is a language intended to be embedded into another program and used to harness its features in extension scripts. The list at
* http://en.wikipedia.org/wiki/Categorical_list_of_programming_languages#Extension_languages
gives us:
*Guile 
*Lua 
*AutoLISP (specific to AutoCAD) 
*REXX 

-- MirkoBlueming