xpybutil is an abstraction over the X Python Binding (xpyb - the Python version
of XCB). It exists because xpyb is a very low level library that communicates
with X.

The most mature portions of xpybutil are the ICCCM and EWMH modules. Each
implement their respective specifications of the same name. The EWMH module
also implements the '_NET_WM_WINDOW_OPACITY' and '_NET_VISIBLE_DESKTOPS'
non-standard features. The former is widely used by compositing managers and
other utilities (i.e., xcompmgr and transset-df) while the latter is used by my
fork of Openbox called Openbox Multihead.