Inspired by Lex (posted 2016-08-23).
Breaking News: Das Böse ist nicht immer hässlich. (posted 2015-11-13).
Emacs Lisp doesn't have closures. Well, until recently, that is. But simple closures can be easily emulated. (posted 2015-10-16).
Type tagging wraps invocation arguments in objects of a different type to select a different instance of an overloaded construct and thus a different processing policy for the argument. This can be done at no cost at runtime and with a reasonably nice syntax. (posted 2014-09-05).