This article is from the Frequently Asked Questions for Linux, the Free/Open Source UNIX-like operating system kernel that runs on many modern computer systems. Maintained by David C. Merrill with numerous contributions by others. (v1.0).
A: Yes. Linux uses XFree86 (the current version is 4.0, which is based on X11R6). You need to have a video card which is supported by XFree86. See the XFree86 HOWTO for more details.
Most Linux distributions nowadays come with an X installation. However, you can install or upgrade your own, from ftp://metalab.unc.edu/pub/Linux/X11/ and its mirror sites, or from http://www.xfree86.org/.