The most complete Open Source Java CRM + GroupWare suite including: sales automation, customer service, intranet, email marketing, content management, bug tracker, project manager, social networks integration, webmail, calendar, forums, file sharing.
There are indeed a lot of features here, but there are also a huge number of security vulnerabilities. Normally I'd try and submit patches but there are really too many to make it worth my time. An unauthorized user can navigate directly to the admin or setup pages and execute arbitrary SQL statements. Passwords are stored in plain text within the database and trivially encoded RIGHT IN THE COOKIE. File uploads can be used to gain shell access to the hosting server. A lot of work has gone in to this software, but security has been completely ignored.
No or small Community. Too much errors.