DBabble for Linux

From NetWin:

DBabble for Linux allows users to send encrypted instant messages, have private conversations, and create and participate in private or public chat rooms and discussions. Users communicate with the chat server using either a web browser, or a client. Users can send instant messages to groups of users, receive email copies of their instant messages or new discussion group articles, and they can send and receive instant messaging from email addresses and mobile phones (via an external sms email gateway). Discussion groups/forums can optionally be linked to external usenet (NNTP) groups and/or made available to NNTP clients. A single DBabble chat server can support thousands of simultaneous online users and can optionally be isolated from outside communication.