phpGroupWare (formerly known as webdistro) is a multi-user groupware suite written in PHP. Its provides a Web-based calendar, todo-list, addressbook, email, news headlines, and a file manager. The calendar supports repeating events. The email system supports inline graphics and file attachments. The system as a whole supports user preferences, themes, user permissions, multi-language support, an advanced API, and user groups.
OpenGroupware.org is a set of applications for contact, appointment, project, and content management. It is comparable to Exchange and SharePoint. It is accessible using Web interfaces or using local clients via WebDAV, GroupDAV, and CalDAV. Custom applications can be developed using the XML-RPC API. OpenGroupware.org runs on almost every GNU/Linux system.
NullLogic Groupware is a modular Web-based groupware and email system designed for contact management and event scheduling. Additional features include private messaging, public discussion forums, webmail, shared bookmarks, file sharing, call tracking, order processing, an XML-RPC API, and integrated POP3 and SMTP servers.
Cerb is a fast and flexible Web-based platform for business collaboration and automation. It helps you remember anything about anyone, collaborate from anywhere, deftly reply to a flood of email, automate, stay informed, capture feedback, track time, flag opportunities, manage tasks, share expert knowledge, and otherwise execute efficiently.
Hep Message Server is software that transfers messages between different messaging systems. Eventually, it should transparently route messages between email, weblogs, and instant messaging. Currently Hep does one thing: fetches news feeds from Web sites and lets you view them in your email client.
i.Scribe is a cross platform email client, address book, and calendar. It is small, fast, and easy to install. It has multi-language support, and currently includes English, French, Chinese Traditional,Italian, Portuguese, Brazilian Portuguese, Japanese, Vietnamese, Czech, Polish, Spanish, German, Russian, and Dutch translations. It is very expandable via a plugin interface, and uses its own HTML engine (and not IE when run on Windows). It supports POP3, [E]SMTP, MIME, IMAP4, and MAPI. An integrated contact database and calendar are included.
IGSuite is a Web-based groupware collaboration suite. It gives you a "box" of applications that includes wiki, email, documents, calendar, tasks, fax, contacts, notes, links, and more. The power of collaboration comes in when these individual suite components are shared and used within a group. It strives to provide location independence, platform independence, machine independence, and browser independence.