From B Labs
Bopup Communication Server is a secure messaging suite designed to provide efficient and private communication over networks of any size. The server meets most of the critical business needs, such as centralized management, the Active Directory (LDAP) support, message logging. It can be easily deployed over the business infrastructure to unite the entire company's offices and other locations into one internal IM workspace with control over messaging groups, user permissions to view others and send messages, a message archive with printing support.
Since the server stores and delivers offline messages, users never lose information they are supposed to receive. Messaging is encrypted with strong algorithms so personal and group conversations are safe and secure even if messages are sent via the Internet. Users can send messages with formatted text, links and graphic emoticons (smileys), organize their personal Contact Lists, access their contacts from any workplace and see who is online and available for communication. The client software can be configured on the server to run in the Confirmation Mode, which means that the client pops up every time a new message is received and keeps the window on top until the user confirms the message. The server supports various modes to
1 GHz processor, 512 MB of RAM, 70 MB of free disk space, TCP/IP connection