From LQWiki

Ratpoison is a minimalist window manager that was designed to be fast and efficient. It loads up quickly and maximizes every window to fit the display. If desired, windows can be split into frames and tiled. ratpoison has a keyboard-driven interface similar to that of GNU Screen.

See also

• http://en.wikipedia.org/wiki/Ion_(window_manager)
• ratpoison: Say good-bye to the rodent (www.nongnu.org)