I recently discovered Slate, an open-source window-management tool for Mac OS X.

It is very cool, mainly in that it is very configurable (but with a reasonably readable syntax for its configuration file).

Perhaps the most important thing to say is: Do not judge it solely based upon its default configuration file, which is very bare bones and does not illustrate anything near the full feature set that it offers.

Instead, I recommend one at least read over Tristan Hume'e blog post, which advertises Slate much more effectively than the project’s github page. The blog post describes some of the crucial features that are not exposed in the default configuration. In particular, the window-switcher shortcut, which overlays each window with a letter to give that window focus, is much more tile-friendly if you also turn on

config windowHintsIgnoreHiddenWindows false
config windowHintsShowIcons true

You can see this and other custimzations I have made for myself in my own .slate file, which I keep with my other dotfiles in my public repository.