The Common Lisp User Interface Environment (CLUE) is a GUI library based on the X Window System and modeled on Xt. CLUE extends the CLX interface to provide an architectural model for the construction of interactive Lisp applications. CLUE could be described as a translation of the Xt "intrinsics" into the domain of Common Lisp and CLOS.

CLOCC contains a version containing all known bugfixes here. It also uses common-lisp-controller.