i3 - A dynamic tiling window manager designed for X11, inspired by wmii, and written in C.
TrackDuck - Visual feedback for web design and development.
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.
Valist - Automatically created staging environments for every update with a shareable link for testing
Openbox - Openbox is a highly configurable, next generation window manager with extensive standards support.
Usersnap - Usersnap is a customer feedback software for SaaS companies that need to constantly improve and grow their products.