DEPRECATED - This is now hosted at https://github.com/Yeraze/ytnef
ytnef is a program to work with procmail to decode TNEF streams (winmail.dat attachments) like those created with Outlook. Unlike other similar programs, it can also create vCalendar/vCard entries from meeting requests, address cards, and task entries.
Rendezvous is an open source web-based collaboration suite including e-mail, calendar, tasks, contacts, documents, projects, rss reader and mobile access. It features a rich user interface based on Adobe Flex.