With this "window manager" I finally started to dominate X windows. The program was full of bugs, had much potential of inventing quickly new approaches in handling the set of window, and integration of applications in linux was inexistent: integration was done manually by switching from one widnow to another.
The first big annoying bug discovered thanks to SF was the key repeating bug
Years passed by and I started to notice annoying flicker: First I started to apply double-buffering to the WM window ornamentation -- the window titles. That helped.