Some years ago, I wrote a window switching utility, an Alt-Tab replacement, in C: http://blogs.gnome.org/nigeltao/?s=superswitcher.

Given the trend in Linux UIs like GNOME3 and Unity, I went all in and wrote my own window manager instead. It's not the first window manager written in Go (and mine re-uses +Andrew Gallant's xgb library), but it's been my day-to-day window manager for over a month now. Sure, I could have configured awesome or xmonad instead, I guess, but where's the fun (and naming rights) in that?

http://code.google.com/p/taowm/
Taowm is The Acutely Opinionated Window Manager. It is a minimalist, keyboard driven, low distraction, tiling window manager for someone who uses a computer primarily to run just two GUI programs: a web browser and a terminal emulator.