123wm

Invoke it in X terminal emulator and the terminal will be the bottom window.

keybind

• Mod-j / Mod-k to change left window and focus it
• Mod-l / Mod-h to focus right / left window
• Mod-; to focus bottom window
• Mod-m to maximize bottom window and focus it
• Mod-t to swap left and right window
• Mod-u to maximize left window
• Mod-r to return to normal state

In normal state focus follows mouse pointer.