Wow, I have fond memories of using WindowMaker. I was really excited to see some recent development with new featuers this past summer (http://windowmaker.org/news.php). I spent a few days with it, I was surprised at some of the defaults. For instance, click to raise isn't enabled by default. That's probably how I used it all those years ago. Anyway, I agree it's lovely. The main things I was missing were modern looking applets (but the Wolfenstein-face CPU monitor is classic), and also better compositor integration (for stuff like expose-style window switching).