XCB
lastmod 2020-12-31created 2020-09-052 edits
XCB (X protocol C-language Binding) is a C language binding for the X Window System in computing. It is implemented as free software and aims to replace Xlib. The project was started in 2001 by Bart Massey.
Xlib/XCB provides application binary interface compatibility with both Xlib and XCB through an incremental porting path. Xlib/XCB uses the protocol layer of Xlib but replaces the Xlib transport layer with XCB, and provides access to the underlying XCB connection so that XCB can be used directly. Most operating systems use Xlib/XCB for their X11 implementation, because it allows an application to open a connection to the X server through multiple libraries and use both XCB and Xlib.