Wlroots is  modular Wayland compositor library,
it provides backends that abstract the underlying display 
and input hardware, including KMS/DRM, libinput, Wayland, 
X11, and headless backends, plus any custom backends you
choose to write, which can all be created or destroyed at 
runtime and used in concert with each other.
wlroots provides unopinionated, mostly standalone implementations of 
many Wayland interfaces, both from wayland.xml and various protocol 
extensions.

Wlroots provides several powerful, standalone, and optional tools that
implement components common to many compositors, such as 
the arrangement of outputs in physical space.
Provides an Xwayland abstraction that allows you to have excellent
Xwayland support without worrying about writing your own X11 window 
manager on top of writing your compositor.
Wlroots provides a renderer abstraction that simple compositors can use 
to avoid writing GL code directly, but which steps out of the way when 
your needs demand custom rendering code.