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

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

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

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

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

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

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

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

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

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

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/

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

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/