i3 - A dynamic tiling window manager designed for X11, inspired by wmii, and written in C.
Headspace - Meditation made simple. Brilliant things happen in calm minds.
awesome - A dynamic window manager for the X Window System developed in the C and Lua programming languages.
Sattva - Guided meditations to inspire you to meditate every day
dwm - dwm is a dynamic window manager for X. It manages windows in tiled, monocle and floating layouts. All of the layouts can be applied dynamically, optimising the environment for the application in use and the task performed.
Sway - Sway is a drop-in replacement for the i3 window manager, but for Wayland instead of X11.