I wrote something like this once, and had maybe 3-4 applications that I wanted to use with it. mplayer was one of them, and it broke with my straightforward and absolutely reasonable window manager. It did display only a quarter of the movies since it thought the video window was fullscreen but it was only a quarter of the screen. The reason was a bug in mplayer's source code. It did not expect to be resized once and only once and being mapped only afterwards.
Another story, I've been an icewm user for many years and I absolutely loved it. But at some point the bitrot was too much. Windows that didn't gain focus because of newer unimplemented client<->WM protocols, clients that crashed for hard to debug reasons, and so on. There are still some patches being developed for icewm that try to make it work with some newer clients. And there are workarounds on top of workarounds for fighting with Java clients, but at some point I decided it was too buggy and switched.
Writing a window manager could be such a nice project if wouldn't mean implementing terrible but necessary protocols, and fighting with all the bad X11 clients out there.
Another story, I've been an icewm user for many years and I absolutely loved it. But at some point the bitrot was too much. Windows that didn't gain focus because of newer unimplemented client<->WM protocols, clients that crashed for hard to debug reasons, and so on. There are still some patches being developed for icewm that try to make it work with some newer clients. And there are workarounds on top of workarounds for fighting with Java clients, but at some point I decided it was too buggy and switched.
Writing a window manager could be such a nice project if wouldn't mean implementing terrible but necessary protocols, and fighting with all the bad X11 clients out there.