x.org is a single-letter second-level internet domain name.
It may also refer to:
X.Org Foundation, a community-based foundation which took over X stewardship in 2004 X.Org Server, the reference implementation of X developed by the Foundation X.Org, the organization in charge of X standards from 1999, as part of The Open Group
See also x.com X Window System, a windowing system for bitmap displays, common on UNIX-like computer operating systems