I wasn't entirely sure what to make of this.

I wasn't entirely sure what to make of this. I like OpenSim, though it seems closer to the open-source release of Second Life that it was based on, than a lot of the VR stuff in development now, or just released. And OpenSim  is primarily a a way of creating virtual worlds first, virtual reality second.  Most times for me it resembles a third person view video game, an that's OK. With my vision (on bifocals now) it's unlikely that I'll be using some form of VR headset (though I'll certainly try them out), and immersion is key to VR. Your senses have to convince you that what you experience is real. In OpenSim though, it's more that you identify with your avatar.

I'm happy with that, but who knows what's going to be adopted wholesale as a VR system of choice? The chances are though that (like video recorders and personal computers) initially there will be lots of different VR systems about but that later 2-3 will become far more popular than the others and set the standards.  If I read this article correctly, it's suggesting that these different systems would be better served by being translatable to each other, so that a user in one system  could travel to another, perhaps bringing their virtual assets with them.

If that's the case, then there might be any number of virtual worlds and virtual destinations you'll be able to visit, provided (I'm guessing) you have the right hardware to do so.
http://www.hypergridbusiness.com/2016/08/the-path-to-a-vr-metaverse