XFree86 is the Open Source port of X.Org's X11R6.6 release that supports several UNIX(R) and UNIX-like (such as Linux, the BSDs and Solaris x86) operating systems on Intel and other platforms.
See the Copyright Notice.
The sources for XFree86 4.2.1 are available by anonymous ftp from:
Binaries for OpenBSD/i386 3.0 and later are available from:
A list of mirror sites is provided by http://www.xfree86.org/MIRRORS.shtml
XFree86 also builds on other OpenBSD architectures. See section Building on other architectures for details.