This package provides original Debian (with Debian patches already applied, and autotools files updated) sources for the X.Org ('Xorg') X server shipped in a tarball. This enables other projects re-using X server codebase (e.g. VNC servers) to (re-)use officially Debian-supported version of the X xserver for their builds.

Unless you are building a software product using X server sources, you probably want xserver-xorg and/or xserver-xorg-core instead.