Window System itself is built on top of the Render System. Not the otherway around. So X11 is wrong. Forgive my post about Xgl

[microcai]

After digging enough to Render API and Window API, I know that I was wrong.

Wayland is here not for a performance reason, but to design a
windowing system in a right way.

X11 build a Render System inside Window System, and make the Render
System depend on Window System, which is plain wrong.
We can render images without an Window, right?
X makes it impossible to do so. If you want to render images with GPU,
you must use X with DRI. What a stupid idea.

What Wayland try to do is  splitting  the Render System and the Window
System apart.
We render window contents with OpenGL or any render API, then commit
the results to Window System. The Window System itself can use render
API such as OpenGL ( Can by any, but currently weston use OpenGL ) to
composite the results to final screen.

There is no render API defined by Wayland. Great job!
I finally know why Wayland is better than X.

The Wayland itself is network transparently,  you just have to find a
way to render network transparently in order to make Wayland network
transparent.

Wayland will have network transparency if there is an remote render
api. We are lucky enough to have VirtualGL.