In February 2004, with version 4.4.0, The XFree86 Project began distributing new code with a copyright license that the Free Software Foundation considered GPL incompatible.

Most open source operating systems using XFree86 found this unacceptable and moved to a fork from before the license change.

While XFree86 was widely used by most Unix-like computer operating systems before its license change with version 4.4.0, it has since then been superseded by X.org and is used rarely nowadays.

[4] The last remaining operating system distribution to use it was NetBSD,[4] which shipped some platforms with 4.5.0 by default until removing it as obsolete in 2015.

[8][5][6] The XFree86 server communicates with the host operating system's kernel to drive input and output devices, with the exception of graphics cards.

Because the server usually needs low level access to graphics hardware, on many configurations it needs to run as the superuser, or a user with UID 0.

The basic configuration file is /etc/X11/XF86Config (or XF86Config-4) that includes variables about the screen (monitor), keyboard and graphics card.

As newer versions of the (originally freeware) X386 were being sold under a proprietary software license by SGCS (of which Roell was a partner), confusion existed between the projects.

As Linux grew in popularity, XFree86 rose with it, as the main X project with drivers for PC video cards.

In 1999, XFree86 was sponsored onto X.Org (the official industry consortium) by various hardware companies interested in its use with Linux and its status as the most popular version of X.

[10] By 2002, while Linux's popularity, and hence the installed base of X, surged, X.Org was all but inactive; active development was largely carried out by XFree86.

Hours before the feature freeze window for XFree86 4.3.0 started, he committed the XFIXES extension (which he developed himself), without prior discussion or without review within the Core Team.

[21] By the end of the year, due to dwindling active membership and limited remaining development capacity, the XFree86 Core Team voted to disband itself.

The last status change was made in March 2004 and it was communicated that there were delays in setting up a revision control system.