Freedesktop.org
- A free software project to work on interoperability and shared technology for desktop environments for the X Window System.
- http://freedesktop.org/

What is X / X Server / XFree86
- At The Linux Revolution. Information on X / X Server / XFree86. Gain a little knowledge on the graphical interface for Linux.
- http://www.thelinuxrevolution.net/Topics/GUI/What-Is-X.shtml

XDM ThemeStuff
- A set of scripts to make Theming the XDM (X Display Manager) easier.
- http://xdm.house.cx/

X11/Graphics
- Holds graphics X11 programs and libraries. These include programs for the manipulation or conversion of graphics (bitmaps in particular).
- http://hpux.ee.ualberta.ca/hppd/hpux/X11/Graphics/

Xprint
- A X11-based print system and API which enables X11 applications to use devices like printers, FAX or create documents in formats like PostScript, PDF, PCL.
- http://xprint.mozdev.org/

X on TV
- How to set up XFree86 for a TV.
- http://www.sput.nl/hardware/tv-x.html

New Rendering Model for X
- By Keith Packard. Article on current limits and future development of X Windows. [PDF]
- http://www.usenix.org/publications/library/proceedings/usenix2000/freenix/full_papers/packardrender/packardrender.pdf

UTF-8 and Unicode FAQ
- All you need to know to use Unicode/UTF-8 on Unix and Linux systems.
- http://www.cl.cam.ac.uk/~mgk25/unicode.html

X Window System and Motif WWW Sites
- List of over 600 technically-oriented X Window sites: X Consortium, Motif, X Advisor magazine, major X technologies, CDE, internationalization, FAQs, on-line technical papers, on-line tutorials, X for PCs and Linux, and general human-computer interaction.
- http://www.rahul.net/kenton/xsites.framed.html

Open Group Desktop Technologies (X.Org)
- Official distribution of X11.
- http://www.x.org/

Broadway Project
- Running X Window over WWW.
- http://www.broadwayinfo.com/

Keith Packard - Papers and Talks
- X Window related papers and talks.
- http://keithp.com/~keithp/talks/

Inter-Client Communication Conventions Manual (ICCCM)
- Atoms, selections, cut buffers, window manager communication, session management, sharing resources, colors.
- http://tronche.com/gui/x/icccm/