Yes, it's the dreaded under construction page. If you're here to find some information about GNU Arch that is customarily found on this page, here are some links to popular pages. Below that, a brief note about what's going on behind this site (why it's under construction and what it will be like shortly).
Note: Most of these links take you to mirrors of the old site that used to be here.
The old top-level page -- if you are looking for an old link not listed below, try looking here. http://regexps.srparish.net/www
"What is Revision Control" -- a neutral description of what revision control is (not Arch specific although, obviously, reflective of the perspective of Arch's designer). http://regexps.srparish.net/www/revctl-intro.html
"An Overview of GNU Arch" -- a brief list of (some of) the features that most distinguish Gnu Arch from competing systems. http://regexps.srparish.net/www/arch-overview.html
"How Arch Works" -- a high level description of exactly what arch is and does. If you're like me, the necessary vagueness of an "overview" like the previous link can be tantalizing but frustrating. This short paper tries to give programmers and other technical types a slightly deeper picture. http://regexps.srparish.net/www/arch-tech.html
"A Tutorial Introduction to The arch Revision Control System" -- http://regexps.srparish.net/www/tutorial/html/arch.html
The user community wiki -- not something I help to maintain at all but (or therefore :-) a popular alternative to the tutorial. Also a forum where people work on new ideas and designs for improvements to arch. http://wiki.gnuarch.org