X11::xcb is a perl module which wraps libxcb, a library to talk the x11 protocol.

please note that its aim is not to provide yet another toolkit for creating graphical applications. it is a low-level method of communicating with x11. use cases include testcases for all kinds of x11 applications, implementing really simple applications which do not require an graphical toolkit (such as gtk+, qt, etc.) or command-line utilities which communicate with x11.