Years ago, in college, I decided I needed a big programming project to help sharpen my skills. I had recently read "Snow Crash" and decided (together with a couple of friends of mine) to create the Metaverse.
We didn't just want to build a client/server system though, it was going to be peer-to-peer, anyone could set up their own 3D world and link to other people's worlds.
It was outrageously ambitious, the Virtual Object System / Interreality Project managed to attracted a small community, although the software barely worked.
I spent about five years and countless hours working on it. Eventually technologies with a similar vision but more development resources sprung up, like Second Life.
Now, I don't think my project would have ever succeeded as an open source alternative to SL. There were some fundamental technical flaws as well as simply being too much work for one person to do.
But ultimately it worked out. I learned a lot about 3D graphics, distributed systems, and managing an open source community. The first one helped me get my first job, the second helped me get my current job, and the third helped with the success of the http://commonwl.org project.
So I think it was worth it, even if the effort ultimately failed. With VR starting to emerge as a more viable technology, there might still be an opportunity for an open, federated 3D VR social space. But I don't think I would try again without a full development team to back me up.
This is a really long winded way of saying that mastodon is incredibly exciting. One of the things that I hoped for in my project was to see it take off and see what people would do with it, and that never really happened. But to be part of another community enabled by technology with similar values is gratifying. thanks @gargron
Interestingly, while Second Life rode a huge wave of hype for a while, they never open sourced their core technology (at least, not when it woul have mattered) so these days nobody talks about SL any more.