The Apache Project OpenMeetings has had an update and is definitely moving towards becoming an interesting alternative to some of the commercial offerings that are available via the web. The reason for hosting your own conferencing tool is that integration with PBX and other internal systems may make this approach more valuable for businesses.
Openmeetings provides video conferencing, instant messaging, white board, collaborative document editing and other groupware tools using API functions of the Red5 Streaming Server for Remoting and Streaming.
You can download the server from here
The main highlights of the app are
File explorer built in for sharing files
Audio and Video Conference
Private messages
Screen Sharing and Recording
Calendar and Invire management.