xproto: xproto (C prototypes for X Window System Core Protocol) xproto: xproto: xproto is part of X11. xproto: xproto: For more information about the X.Org Foundation (the providers of the xproto: X.Org implementation of the X Window System), see their website: xproto: xproto: http://www.x.org xproto: xproto: xproto: