The xcb-util module provides a number of libraries which sit on top of
libxcb, the core X protocol library, and some of the extension libraries.
These libraries provide convenience functions and interfaces which make the
raw X protocol more usable.  Some of the libraries also provide client-side
code which is not strictly part of the X protocol but which have traditionally
been provided by Xlib.

The util-cursor module implements the XCB cursor library, which is th XCB
replacement for libXcursor.

WWW: https://xcb.freedesktop.org/