IntraMessenger 6G 1.0
Create you own Instant Messenger at office (for LAN or internet).
Server is PHP + MySQL (open source).
The administrator can choise all options, for display, contact manage, lock...
He can force nickname to Windows username (if computers on a domain, it's a LDAP authentification) or let users choise by themself.
He can force or not user to use password, limit (or not) maximum simultaneous users, online users...
Server can be public or locked...