1wm

The smallest, actually usable window manager.

• ~20 LOC.
• No modes, no mouse control, no virtual desktops, no menus.
• No configs, no eye-candy, not standards-compliant.
• Only one full-screen window visible at a time.
• Depends only on Xlib.

Because software should be small, hackable and fun, not a damn technical debt. You can grasp this one in <5 minutes.

The essential things a window manager should let me do are:

• Launch applications (dmenu): Mod4 + e.
• Switch between windows: Mod4 + n.
• Close windows: Mod4 + q.