Apache OpenMeetings is a popular and free alternative for web conferencing software. The release of OpenMeetings 6.0 features multiple security improvements. 

Powered by Apaches License 2.0, OpenMeetings is a free and open source software. It is used for online training, presenting, web conferencing, document editing, user desktop sharing, and collaborative whiteboard drawing. OpenMeeting using API functions of the Red5 Streaming Server for Remoting and Streaming.

The video call software has multiple features that make it a perfect collaborative tool, or groupware, as well.