It is descended from the GUI system Dynamic Windows[4] of Symbolics' Lisp machines between 1988 and 1993.
A descendant of the Symbolics Lisp machines GUI framework, CLIM is powerful but complex.
Although many commercial Common Lisp implementations actually support it, it doesn't seem to have seen a lot of use.
It is free and open source software released under a GNU Library General Public License (LGPL).
CLIM has been designed to be portable across different Common Lisp implementations and different windowing systems.