Wayland

http://cgit.freedesktop.org/wayland/wayland/tree/src/wayland-client.h
http://cgit.freedesktop.org/wayland/wayland/tree/src/wayland-server.h
http://cgit.freedesktop.org/wayland/wayland/tree/src/wayland-egl.h

That's it. Those three tiny header files is all you need to be able to host or interface with a Wayland server, create and manipulate windows, get input device events, or get an EGL context for use with OpenGL or OpenGL ES (your choice). There are no configuration files (everything is autodetected and/or delegated to the kernel, enumerating display adapters, adapter outputs, input devices, etc. is done by traversing the mounted devfs file system tree).

You can use this as your starting point to implement a full blown DWM or X Windows layer, or you can use it write client applications that integrate nicely with any active Wayland server including Wayland-based DWM.

Why are you still using X Windows?

>>7
Commenting header files slows down the compilation process. External documentation is preferred. It's not like you can read the comments in Java, C#, etc. programs due to the different compilation model anyway, people there consult the external documentation.