An interesting aspect of Assemblive for you, hackers, is that you can embedd a 3D+VOIP widget into any web site. You can add realtime interactions and self awareness of your visitors with only a few lines of code. Here is a screencast of it (sorry for the french accent ;) http://aworldforus.tumblr.com/post/287534616/assemblive-widg...
Yes, we use Unity3D, a web plugin to run hardware accelerated 3D in the browser. They don't support Linux yet, but now that they raised a huge amount of money from Sequoia they might work on it (if they want to support ChromeOS they'd better hury)
Comparing Unity3D to O3D is a bit like comparing the Unreal Engine to OpenGL. Unity3D is much higher level, and provides lots of things like Ageia PhysX™, etc.
On the other hand not having to install a plugin would be a killer, so we are definitely keeping an eye on WebGL...
Unity3D is much more mature and full featured right now (and even more when we started working on this). We are looking into WebGL too, to soon for prime time but promising.
an interesting idea, but is the 3D really necessary? I would think a multi-stream voice / video chat in normal window type interfaces like we're used to online would be better.
Even better would be to integrate with existing voice chat apps, like voice chat in googletalk, but with support for "conference calls" in video and voice.
I just don't see this as a good idea, the implementation looks great though.
The whole idea of this is to allow large groups events. Think 20+ participants. Using 3D allows us to spatialize the event, while staying very dynamic. Groups can form, change, recreate just by moving. The sound is spatialized too, so it could scale to hundreds, thousands of persons. Just using regular voice would make an awful noise. 3D splits group very naturally, while staying dynamic and most of all, intuitive because it's very similar to regular networking events. It could obviously be done by creating voice groups on a "flat screen", but we strongly believe in the power of real world analogies, to make it immersive and help people understand how to behave in this.