Trillian is a proprietary multiprotocol instant messaging application.

FastMail is an email service offering paid email accounts for individuals and organizations.

Jitsi (formerly SIP Communicator) is a free and open source multiplatform voice (VoIP), videoconferencing and instant messaging application.

Movim (My Open Virtual Identity Manager) is a distributed social network built on top of XMPP, a popular open standards communication protocol.