i3 - A dynamic tiling window manager designed for X11, inspired by wmii, and written in C.
Openbox - Openbox is a highly configurable, next generation window manager with extensive standards support.
Wayfire - Wayland compositor with 3d effects.
Sway - Sway is a drop-in replacement for the i3 window manager, but for Wayland instead of X11.
awesome - A dynamic window manager for the X Window System developed in the C and Lua programming languages.
KDE Plasma Desktop - Plasma Workspaces is the umbrella term for all graphical environments provided by KDE.