"where is Web3D?"
Today, the most advanced, flexible and widely accepted Web3D,
virtual world platforms are 'Second Life' (with over 15 million
'residents'), created by Linden Labs, and it's open source
equivalent: 'OSGRID', based on Opensim. These can be accessed
from most modern Windows or Mac computers, requiring nothing
more than a broadband connection. Most of the current virtual
Web3D environments can also be accessed whilst ‘on the go’ using 
laptops or tablets and a wireless connection.

Beyond this, organisations are also turning to more advanced
platforms based on game engine technology such as Unity 3D which
enables one-click browser access to photorealistic environments. 
Platforms based on WEBGL technology are also starting to emerge.
who?
what?
where?
why?
how?
next?