Below are links to all the software released free and open source by
ArsDigita, including the ArsDigita Community System (ACS) and various
free tools.
Eve Suggests:
ArsDigita Community System 3.4.10, the best version
of the ACS ever. Without too much of a learning curve, you can use this software
to create a collaborate web service. This version of the ACS contains many
modules, including ecommerce, intranet, portals, bboard, education, calendar,
and much more. Full Documentation.
ArsDigita Community System 4.2 has fewer modules than
ACS 3.x, but it does contain a beautiful Content Management System. If you want
to use this version, first install the core and then install
any additional packages (software listed below of type "4.x TCL Package") that look interesting
to you.
There are numerous Free Tools which might
be useful for your web service.