i3 - A dynamic tiling window manager designed for X11, inspired by wmii, and written in C.
Treehouse - Treehouse is an award-winning online platform that teaches people how to code.
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.
Teachable - Create and sell beautiful online courses with the platform used by the best online entrepreneurs to sell $100m+ to over 4 million students worldwide.
Openbox - Openbox is a highly configurable, next generation window manager with extensive standards support.
PowerSchool - PowerSchool provides a K-12 education technology platform for operations, classroom, student growth, and family engagement.