libxcb provides an interface to the X Window System protocol, which replaces the current Xlib interface. It has several advantages over Xlib, including:

- size: small, simple library, and lower memory footprint;

- latency hiding: batch several requests and wait for the replies later;

- direct protocol access: interface and protocol correspond exactly;

- proven thread support: transparently access XCB from multiple threads;

- easy extension implementation: interfaces auto-generated from XML-XCB.