mcwm is a minimalistic floating window manager for the X Window System. It is built directly on top of XCB, the C binding for the X11 protocol. It doesn't use the Xlib API at all.

All functions are available from the keyboard, but the mouse can be used for moving, resizing and raise/lower.

The window layout is like a many other traditional floating window managers. It doesn't move windows automatically for you, with one exception: If you remove or tilt a physical screen and the new X root window is suddenly much smaller in any direction, mcwm will move and/or resize windows so all mapped windows continue to be fully visible.