But there are
alternatives to Word which will do the same thing. TeX is one, PDF is
another, XML is a third.
HTML (with forms, etc) may also be a very fine answer, if it can be
generated (say) by PHP from (say) XML, or indeed from any database back-end
(such as MySQL, etc).
In fact, GC's voynich.info site has MySQL installed, and is allowed to have
up to four individual active databases running, so this is entirely within
the realms of possibility. :-)
An intelligent use of HTML would almost certainly enable the broadest level
of collaboration practical - historically speaking, that's also what
Berners-Lee originally intended the web to be like (this was, ummm, way
before the banner-ad guys parked their trucks on every page). :-)
There is also free software for collaborative web
pages (once discussed on-list).