XFree86

XFree86 is a free (Open Source) implementation of the X Window System which runs under Linux, FreeBSD, NetBSD, OpenBSD, Solaris and Windows NT (possibly other Unix-like OS's?). Currently (01OCT2001), XFree86 supports the X11R6.5 spec, including the GLX and Render extensions. Anyone who's interested can get it at http://www.xfree86.org