Binary package “x11proto-xext-dev” in ubuntu xenial

X11 various extension wire protocol

 This package provides development headers describing the wire protocol
 for various extensions, the client-side libraries of which are provided
 in the Xext library.
 .
 More information about X.Org can be found at:
 <URL:http://www.X.org>
 .
 This package is built from the X.org xextproto proto module.