BigBlueButton is the rising star of open source video conferencing. It supports sharing of slides (PDF and PPT), video conferencing , whiteboard, chat, voice (using Asterisk or FreeSWITCH), and desktops.
Ekiga (formely known as GnomeMeeting) is an open source video conferencing and VOIP software for GNOME. Ekiga uses both the H.323 and SIP protocols. It supports many audio and video codecs, and is interoperable with other SIP compliant software and with Microsoft NetMeeting.
Dimdim was an open source web conferencing software with features like Application, Desktop and Presentation sharing with audio and video conferencing and chat. DimDim software has been acquired by Salesforce.com.
VMUKTI is Social, Web 2.0, SaaS, Peer-to-peer, & VoIP Open Source multi-Party Conferencing (like video and web conferencing WebEx) Broadcasting , Collaboration And CMS platform for Web & Mobile users Video/ Audio/ Presence & Content.
QuteCom (formely WengoPhone) allows you to make PC to PC video and voice calls, and to integrate all your IM contacts in one place. Please note that QuteCom do not integrate yet Video Conferencing.
OpenMeetings is a free open source video and web conferencing software. You can use your microphone or webcam, share documents on a white board, share your screen or record meetings. It is available as hosted service or you download and install a package on your server with no limitations in usage or users.
