OpenFire is an opensource real time collaboration server that use XMPP (also called Jabber) to create istant messaging applications.
The official web site also says “Openfire is incredibly easy to setup and administer, but offers rock-solid security and performance” and I can confirm you that it’s really true!

In this article we’ll use the Adobe Collaboration Service components (codeName : CoCoMo) to develop a simple eLearning platform with following features:
1) WebCam
2) Audio on/off
3) User List
4) Text Chat
5) Shared notes
6) Shared whiteboard