EGroupware is a Web-based groupware suite. It contains many modules, including Calendar (personal calendar and group scheduling, notifications and alarms), Mail (IMAP only), InfoLog (todos, notes, and phone calls linked to contacts/CRM), Contacts (an address book for storing and sharing contact information), ProjectManager, Tracker (bug or incident tracking), TimeSheet, SyncML, CalDAV & CardDAV support, and SiteMgr content management
Easta is a Napster-inspired peer to peer filesharing system, built to operate entirely over email (POP/IMAP+SMTP). More people have access to email than any other service, and in addition it gives easy access to file-sharing for the 90% of the planet stuck behind a firewall without a SOCKS connection. There's some nice side-effects too, such as asynchronous downloading, even when you're offline.
Easy Cast du Multi Hub (ecmh) is a networking daemon that acts as a full IPv6 MLDv1 multicast router. This allows IPv6 multicast routing on Linux. It will also allow IPv4 to IPv6 and IPv6 to IPv4 translation of multicast traffic, allowing multicast where it is not yet available otherwise. This code runs on the SixXS POPs, where this daemon runs on the POPs and let it easily do multicast IPv6. This allows the m6bone to grow and provide IPv6 multicast to end users. Users can deploy this software to enable their networks with multicast.
Echomine Feridian is an easy-to-use Java API that gives you quick and easy access to the XMPP network used in IM services such as Google Talk. The API allows you to communicate with Jabber/XMPP servers for sending and receiving instant messages, presence management, and custom extensions to the XMPP protocol.
Effusia Business Messenger is a cross-platform, centrally managed, internal instant messaging and presence communication tool for small to medium enterprises. The system comprises a client, a server, and an integrated Web based administration tool. Effusia focuses on providing real-time business communication combined with simple deployment, easy administration, and a friendly end-user experience.