x11proto-core-dev 7.0.10-2 (amd64 binary) in ubuntu gutsy

 This package provides the wire protocol for the core X11 protocol, and also
 provides a number of utility headers, used to abstract OS-specific functions.
 .
 This package deprecates 'x-dev', a package from the monolithic builds of
 XFree86 and X.Org.
 .
 More information about X.Org can be found at:
 <URL:http://xorg.freedesktop.org>
 <URL:http://lists.freedesktop.org/mailman/listinfo/xorg>
 .
 This module can be found as the module 'proto/X11' at
 :pserver:anoncvs@cvs.freedesktop.org:/cvs/xorg