The attached program works the same in McCLIM and Lispworks CLIM, except McCLIM gets into an infinite loop (CMUCL latest) unless incremental-redisplay is enabled. The program just wants its displayed output to track resizing the frame from the window manager. The attachment should run correctly. But then comment out the :incremental-redisplay as shown below and trouble is at hand. (defclass test-pane (application-pane) () (:default-initargs :display-function 'tpdf ;;; YIKES - in McCLIM; without this, infinite loop!! ; :incremental-redisplay t ; :display-time :command-loop )) ;;; Paul