Email and Collaboration
Citadel is a turnkey open-source solution for email and collaboration. The Citadel system is extremely versatile. It provides numerous front ends to present to users, such as a text-based interface, an AJAX-style web interface, and many popular PIM clients using SMTP/POP/IMAP. All of these can be used simultaneously.It’s also extremely scalable. Not only can a well-equipped Citadel server support a large number of concurrent users, but you can also build a distributed network of Citadel nodes that share rooms and their content.
Features include email, calendaring, address books, bulletin boards, instant messaging, and more … all in one tightly integrated server package. Unlike other open source groupware systems, all of Citadel’s data stores are built-in. All that tedious mucking about with dependencies and config files is a thing of the past.
Standards-compliant e-mail built in: IMAP, POP3, ESMTP.
Group calendaring and scheduling (GroupDAV and Kolab-1 compatible).
Server-to-server replication. Users in any number of domains can be spread out across any number of Citadel servers, allowing you to put data where you need it, and enabling infinite horizontal scalability.
Web-based access to email, calendars, and everything else through a powerful AJAX-style front end.
Citadel is true open source software. Unlike other groupware servers, it isn’t a cut-down version of an expensive proprietary “pro” version. We make our very best work available to everyone on the same terms. 100% of our code is covered by the GNU General Public License (GPL3).
Very nice, gives me a lot of inspiration being right in the midst of a redesign. It’s all in the details and comment forms are definitely overlooked more often than not. Time well spent on this post.