Well, whether or not it's actually faster, it sure feels orders of magnitude faster. xmonad may use only 1000 lines of code for the window manager itself, but

Well, whether or not it's actually faster, it sure feels orders of magnitude faster. xmonad may use only 1000 lines of code for the window manager itself, but that's backed up by a rather large Haskell library (particularly when loading lots of contributed code). I know the resident memory size of xmonad is gigantic compared to musca. Manipulation of those large memory structures may be relatively slow, even if you use efficient algorithms (particularly on systems like my own, which use so much memory that some of my apps are swapped out). As for Haskell being high level and safe, I appreciate that. But it really does me little good when I don't know Haskell. The musca window manager doesn't require knowing Haskell, and I think it's just as flexible, and certainly high level enough (you can use bash scripts, or really any language you want to configure it) and safe enough for me not to have any issues with it. Sure, using Haskell might be better, if I knew Haskell. But I don't, and I'm not going to learn it any time soon. So it's a moot point.