Even though Second Life gets the lion's share of the attention, there are several other virtual world systems out there, including some that are fully open source. One such is Croquet:
Croquet is a powerful open source software development environment for the creation and large-scale distributed deployment of multi-user virtual 3D applications and metaverses that are (1) persistent (2) deeply collaborative, (3) interconnected and (4) interoperable. The Croquet architecture supports synchronous communication, collaboration, resource sharing and computation among large numbers of users on multiple platforms and multiple devices.
The ideas behind Croquet are undeniably powerful, but it's always looked a little clunky when I've investigated it, more like a research project than anything that you might use. In other words, a solution in search of a problem.
Well, the problem has just turned up, and involves creating a secure virtual workspace for distributed teams. In the corporate context, the Second Life gew-gaws are less important than functionality like security and the ability to collaborate on any application. A new company called Qwaq, which includes many of the key people from the Croquet project, has been set up to meet that need.
It adopts a hybrid approach for its licensing: the core code is Croquet, and hence open source, but Qwaq adds proprietary elements on top. Obviously, I'd prefer it if everything were free code from the start, but it's understandable if new companies are cautious when dabbling with this tricky open source stuff. The existence of Qwaq, which obviously has a vested interest in the survival and development of Croquet, is already good news for the latter, but I predict that in time the company will gradually open up more of its code in order to tap into the community that will grow around it.
Its business model could certainly cope with that: it offers two versions of its product - one as a hosted service, the other run on an intranet. Although it is true that other companies could also host and support the product in this case, Qwaq has a unique strength that comes from the people working for it (rather like the advantage that Red Hat's roster of kernel hackers confers.)
One of the benefits of using Croquet as the basis of its products is that the protocols are open, and this allows Croquet-compatible products to interoperate with Qwaq's. This means that the dynamics of the Croquet ecosystem are similar to that of the Web, which is never a bad thing.
At the time of writing, there's not much to see on Qwaq's site, but I imagine that will change soon, and I'll update this post to reflect that (and also be writing elsewhere about the technology and its applications). In the meantime, Qwaq's arrival is certainly welcome, since it signals a new phase in the roll-out and commercialisation of standards-based virtual spaces. I'm sure we'll see many more in the future.
Update: The Qwaq site has now gone live, with some info and a screenshot of the Qwaq Forums product, as well as a link to a datasheet. There is also a short press release available.