mwm

For the true minimalist:

• ~20 LOC.
• No default keybindings.
• No title bars, no status bars, no buttons, no borders, no menus, etc.
• No mouse control.
• No virtual desktops.
• No configuration files.
• Absolutely adabptable to your needs.
• Includes just what is strictly needed.

mwm just loops through X key press events and lets you bind actions to key presses. It provides two macros: grab and on. You first grab the key (e.g.: grab("Return", Mod4Mask)), then you bind an action to it (e.g.: on("Return", system("xterm &"))). More than one action can be provided (e.g.: on("Tab", XCirculateSubwindowsUp(d, r); XSetInputFocus(d, e.xkey.window, 0, 0)))).

Dead simple.