Jamm (Java Mail Manager) is a web application to manage virtual email account information stored in an LDAP directory. It is meant as an administration tool for sites using mail servers, such as Postfix and Courier-IMAP.
Prompt Courier is an instant messaging system intended for use in corporate LAN environments. The system is written in Java so both the server and client portion will work on any Java enabled platform.
a semi-p2p file sharing utility, designed for enterprise. allows specified users access to specified files, on a per-file and per-user basis. downloads are p2p, but there is a server with organizational duties involved.