Development of Window Maker (as in the window manager) unfortunately seems to be almost abandoned. The last few years of it's development saw the inclusion of rather superfluous additional features (e.g., screen capture, hot corners) instead of concentrating on it's main purpose of being a window manager.
It's a pity no one ever tried to replace the WINGs widget set with actual GNUstep components, thus adding the full GNUstep themeability WINGs is not capable of, in order to finally get rid of that crufty NeXTSTEP look.
It's a pity no one ever tried to replace the WINGs widget set with actual GNUstep components, thus adding the full GNUstep themeability WINGs is not capable of, in order to finally get rid of that crufty NeXTSTEP look.