The Lisp-based ScriptingLanguage? used to customise the Emacs programmers' editor.

Note for Lisp programmers: ELisp is dynamically scoped. This affects how global variables in function definitions are looked up. With dynamic scoping the interpreter looks up these variables in the environment where the function is called. What other Lisps do is to use the variable definitions that were present when the function was defined (i.e. lexical scoping). This difference will only effect you if you are trying to do lots of higher-order functional programming in ELisp, but if you do, it will trip you up.