BigBlueButton
- A cross-platform, open source web conferencing system for distance education.
Ekiga - Free Your Speech
- A GPLed SIP and H.323-compatible VoIP, IP telephony, and video conferencing application; formerly called GnomeMeeting. Latest stable release is 3.2.4, 2009-05-20.
Openmeetings
- An open source, browser-based software that can instantly set up a conference on the Web using a microphone or webcam. It is available as hosted service or you download and install a package on your server with no limitations in usage or users. It integrates with Moodle and SugarCRM. Latest release is 1.6, 2010-11-11.
SILC - Secure Internet Live Conferencing
- The SILC Project has developed the Secure Internet Live Conferencing protocol, which provides secure conferencing services. Latest release is 1.17, 2009-01-10