DimDim just released their 4.0 version that has more features and is more compatible with Mac computers (including desktop sharing). The free version includes hosting and scheduling meetings for up to 20 participants and 3 participants plus the host can have active mics at the same time.

They also have an open source version for developers… so, if you’d like to run your own DimDim locally, there you go…

ePresence -> Free and open source tool. Has to be installed on your local server. Technical support is offered by the Open Source Consortium. Their webconferencing and webcasting applications are excellent and feature-rich. It is possible to record both webcasting (broadcasting an event, for instance) and make it available on your website. It is possible to record webconferencing (people interacting with a virtual whiteboard in a virtual room) and make it available as well.

DimDim -> Another open source initiative. You can host online meeting without installing any extra program, just go to their website, create a free account and you are up and running. DimDim allows you to schedule and invite anyone without requiring them to install any plugins. Maximum of 20 users in the free ad-supported version of the online web meeting program, but they offer room for up to 100 people for $495/year and an enterprise edition. You can also install locally and free of charge the DimDim Enterprise edition free of charge (it requires more technical know-how).

Elluminate -> Webconferencing tool with many features. Even though the “looks” are more old-fashioned, this program is very stable and well-accepted in the academic arena. They have good academic packages.

Yugma -> Feature-rich webconferencing tool that has a free version. Yugma offers other versions of their packages that allow you to invite more participants at a time. A plugin is required for participant to view the meeting room. An interesting differentiator for Yugma is that they offer a Skype plugin that works seamless with the famous VOIP client.

Vyew -> Web-based tool that has many important features in their free version. No plugins to download and plans that offer more flexibility and storage are also offered.