http://www.cs.berkeley.edu/~amc/Par/
is the home page for Adam Costello's par program, which is a much
more sophisticated text formatter than the fmt program distributed with
elvis.
ftp://alf.uib.no/pub/vi
is an archive site containing many macro packages and other
information about vi.
http://www.thomer.com/thomer/vi/vi.html
"The VI lover's home page" contains links to a wide variety of vi
documentation, and practically all vi clones. A very good
resource!