XFree86 4.0 was the first official release of the new XFree86 4. XFree86 4 represents a significant redesign of the XFree86 X server. Not all of the hardware drivers from 3.3.x have been ported to 4.x yet, but conversely, 4.x has some hardware support not present in 3.3.x. We've attempted to provide some information about the second point in our Driver Status document. Please check there first before downloading 4.0.1.
The 4.0.1 has a new configuration tool, "xf86cfg". It is work
in progress, but definitely worth trying out. We have also updated the
basic text-based tool "xf86config" to generate config files in
the format required by 4.0.1 (3.3.x config files won't really work
with 4.0.1). We're also on a configuration tool that is built-in
to the X server. An early version of this is included in the release,
and it works well for some hardware. To try it out, just run (as root)
"XFree86 -configure". Each of these configuration options will
give you a reasonable starting point for a suitable configuration file.
We've put some effort into documenting the 4.0.1 config file format,
and you can find that information in the XF86Config manual page. Check
that, the driver manual pages and the related documentation for further
information.
Oh, another thing you might notice is that our documentation is rather patchy. Most of what is present should be in reasonable shape, but there are gaps. We thought it better to leave out docs that were very out of date rather than providing inaccurate and misleading information. We are looking for people to also help fill those gaps in <hint hint :->.
Finally, before you download and install the binary distributions for this release, please have a quick read through the Installation Document. It may save you some time.
The next section describes what is new in the latest version (4.0.1). The other sections below describe some of the new features and changes between 3.3.x and 4.0. There is a lot of new features, and we definitely don't have enough space to cover it all here.