Documentation?

[Mark Wagner]

I'm busy updating the Linux branch of a cross-platform toolkit that
was last updated in 1994.  The big problem I'm running into is a lack
of documentation on how to program for XWindows: the online
documentation I've been able to find is at least as old as the toolkit
-- for example, one has an appendix detailing the changes from X11R4
to X11R5.  Other webpages I've found may be newer, but they don't
mention any dates or versions.

Is there a good online document on how to program for XWindows using Xlib?

Are there programming references for the various extensions, or do I
need to work from protocol specifications and uncommented header
files?

Is this the best mailing list for any questions I have, or is there a
better one?

Thanks,
Mark Wagner