Xdmx is proxy X server that provides multi-head support for multiple displays attached to different machines (each of which is running a typical X server). When Xinerama is used with Xdmx, the multiple displays on multiple machines are presented to the user as a single unified screen. A simple application for Xdmx would be to provide multi-head support using two desktop machines, each of which has a single display device attached to it. A complex application for Xdmx would be to unify a 4 by 4 grid of 1280x1024 displays (each attached to one of 16 computers) into a unified 5120x4096 display.