One of the criticisms towards Wayland is the lack of a Window Manager concept. This to have an option of a different window manager behaviour/experience without needing to write a whole compositor as well. On LWN, daniels confirmed that it’ll become easier with time thanks to libweston.
Quoting daniels (first line/paragraph he’s quoting me):
> Not exactly sure what this allows, but I assume that most of the compositor logic is in this libweston, thereby reducing the complexity creating a different Wayland compositor.
Correct. The idea is to let people write window managers and desktop environments without having to worry about the details of DRM/KMS/GBM, EGL, dmabuf, the Wayland protocol itself, and whatever other plumbing. It’s not there yet, but hopefully in the next year or so it’ll become a really solid viable alternative.