I'm assuming you're referring to "XFree86" which is an open-source implementation of the X Window System (X11) for various Unix-like operating systems.

XFree86 is no longer actively developed, and its use is discouraged. The last release, XFree86 4.8.0, was made in 2007. X.org is the recommended replacement, offering more recent features, better support, and ongoing development.

If you're looking for a modern, free, and open-source X11 implementation, I recommend using X.org.