Timbuktu is a remote control technology for Windows95/98 or Windows NT machines.  Timbuktu allows a user to logon to a remote computer over LAN, WAN, TCP/IP, Internet or RAS connections and interact with that computer as though the user was at the keyboard of the remote computer.  
....   A built-in Intercom lets one talk over the connection and an interactive keyboard Chat feature provides text-based communication in addition to the remote control capability.

Timbuktu Web Site