OpenSimulator is a free tool that allows you to build a cross-platform 3D application server.
So, what is it for ?
Well, it allows developers to create virtual worlds and customize them as they see fit, in the language of their choice (C#, .Net). The goal here is to create virtual environments similar to Second Life.
And why is it cool?
Available on Windows and Linux, OpenSimulator will allow you to design 3D environments of varying sizes that support many users. These users will be able to access it via the protocol of their choice and your metaverse will be realistic with the support of the fundamentals of physics in real time.
OpenSimulator is a little tough to learn, but I’m sure you’ll be able to do great things with this tool.