Dimdim

From Dimdim:

Dimdim is a free Web conferencing service where you can share your desktop, show slides, collaborate, chat, talk, and broadcast via Web cam with absolutely no download required for attendees. The Dimdim Web Meeting service is available in open source and commercial enterprise editions capable of supporting thousands of attendees. And unlike all other web meeting solutions, Dimdim is available in both onsite (you install it on your servers) and hosted (we install it on ours) configurations. Like you, we tried all those other Web conferencing solutions and found them exceedingly expensive, difficult to implement and impossible to customize. So we created Dimdim as the easy, open, and free Web meeting alternative. Dimdim just works - no software to download or maintain, and it takes only a few clicks to join or host your very own meetings.

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