Citadel is a messaging and collaboration platform. While other types of groupware focus on automating business processes, Citadel focuses on connecting communities of people together.

History

Citadel was a Unix BBS system in the 1980's. It has since then evolved in the internet age to become a full-featured collaboration suite.

The "rooms" concept

A Citadel system is made up of containers called "rooms." A room may be used as an email folder, a discussion forum, a real-time chat, a mailing list, a calendar, an address book, an RSS sink ... and sometimes a combination of any of the above. Furthermore, you can replicate rooms between multiple Citadel nodes, allowing you to set up a federated, distributed messaging environment.

Citadel includes capability for:

Standards-compliant e-mail (POP, IMAP, SMTP)

Shared calendaring (GroupDAV, Aethera, and Kolab-1)

Shared address books

Discussion forums

Instant messaging

Collaborative whiteboards on top of the Jabber protocol.

Bulletin Board System (BBS)

The Citadel system provides numerous front ends to present to users, such as a text-based interface, a web-based interface, and many popular PIM clients using SMTP/POP/IMAP. All of these can be used simultaneously.

It's also 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.

Visit the Citadel Homepage.

See Also

Microsoft Exchange Collaboration Portlets - JSR168 complaint portlets to integrate MS Exchange to Enterprise Portals.