nx-x11proto-composite-dev - 2:3.5.99.26-2 main

NX is a software suite which implements very efficient
compression of the X11 protocol. This increases performance when
using X applications over a network, especially a slow one.
.
This package provides development headers describing the wire protocol
for the Composite extension in nx-X11, used to let arbitrary client
programs control drawing of the final image.