@Aeris Irides Originally, yes, #LindenLabs introduced that rating system to #SecondLife as content warnings for sensitive users: If you don't want to see sex and/or gore, don't go to Adult-rated sims. If partial or complete nudity disturbs you, you may want to stay away from Moderate-rated sims as well. When the teen grid was shut down, the rating system was also used to kept users under 18 away from sims that weren't General-rated.

Of course, it also means that the content on the sims has to be appropriate for the rating. The Lindens probably don't take kindly to public sex being allowed and actually happening on General-rated sims if they find it out. On the other hand, I guess they may also go against rating misuse the other way, namely Adult-rated sims with no Adult-rated content. But these may be rare because there's no point in rating a Second Life sim Adult and keeping everything squeaky-clean.

Now, experience has shown us that the Second Life rating system simply doesn't work in #OpenSimulator. It is based on the real-life age of the users, and even in Second Life, it only works with age verification: Only if you can prove that you're 18 or older, you may enter sims with a Moderate or Adult rating.

But #OpenSim doesn't have age verification. The rating system doesn't work as an access restriction system based on real-life age. And the fact that it was originally intended as a content warning system is completely forgotten now.

Add to this the fact that OpenSim doesn't have pre-defined standard grid rules built in. Almost no grid has any rules to begin with, so there's also no written definition of these ratings in OpenSim whatsoever, probably also because many grid owners believe that it's commonly accepted that the definitions are the same as in Second Life.

Without user age verification, the focus has often switched away from the age of the users to the apparent age of the avatars. This, together with a lack of a common mandatory ratings definition, led to this not exactly rare new definition:

• General = G-rated
  
• Moderate = G-rated; nobody knows what the difference to General is
  
• Adult = G-rated, but no child avatars allowed

In part, this is due to misunderstanding on the side of grid owners/sim owners who don't speak English as I've said in the start post. But it can also be wishful thinking by deeply prudish and up-tight people who want all smut gone from the #Hypergrid.

This, by the way, leads to an interesting phenomenon. You can often see it when you attend an event in a place where nudity is not just allowed as per the Adult rating and the implication that it means the same as in Second Life, but encouraged and actually practiced. So you have nude avatars dancing.

Then someone who isn't a regular, who most likely has never been there before, comes teleporting in. Hellos are exchanged. They stay for about five minutes. And then they teleport out without saying a word. Why? Because they've spent these five minutes waiting for everyone's clothes to rez. After these five minutes, however, they came to the conclusion that some of the avatars are actually naked. Thus, they escaped from that cesspool, disgusted and disturbed. They clearly didn't expect an Adult-rated sim to actually have Adult-rated content on it.

Now, why does OpenSim have this ratings system in the first place if it doesn't work? Because it has to stay as close to Second Life as possible so that it can use the same viewers.

Some viewer developers think that adding grid selection is sufficient to make a Second Life viewer compatible with OpenSim, and they wish this was the case so that they don't have to take any extra efforts upon them. AFAIK, there are less popular viewers which are pretty full-featured when it comes to Second Life, but which lack a lot of OpenSim-specific features because the devs lack capacities and motivation to include them. If they only ever use Second Life, they can't even test them in the first place. Even Firestorm has removed the ability to create subfolders under Outfits because Second Life doesn't support them anymore, regardless of them working perfectly well in OpenSim.

This also means that changing OpenSim in ways that replace Second Life features with original OpenSim features is completely out of question. OpenSim needs its own ratings and content warnings system, but that would have to sit next to Second Life's General/Moderate/Adult system in the viewers at first and eventually replace it altogether. Viewer devs won't do that.

What makes matters even more complicated is that the grids run widely different OpenSim versions which viewers have to stay compatible with. #OSgrid is always bleeding-edge. Other grids still run OpenSim 0.8.2.1 or even older. Or they run some fork from 0.7.* times that only had a select few changes from newer versions backported over time, and which are no longer maintained anyway. This explains why Otterland which is stuck on OpenSim NextGen lacks both #BakesOnMesh support and even a fallback for BoM avatars, so it wrecks any and all BoM avatars entering the grid.

Even if OpenSim did manage to introduce its own ratings system, it'd take years for all grids to implement it which would require some grids to shut down for good. On the viewer side, the #CoolVLViewer would be the first to implement it, the #FirestormViewer would follow when they deem it important enough to include it in one of their next releases, and probably all the others would lag behind a lot or never implement it in the first place and become useless for OpenSim.

@Third spruce tree on the left The #SecondLife protocols are open AFAIK.

At least the Second Life viewer API became open when #LindenLabs made the official viewer open-source in 2006.

That already was enough information to develop not only third-party viewers, but a wholly new, free, open-source virtual world system around that API that's very close to Second Life. It's called OpenSimulator, relevant hashtags would be #OpenSimulator and #OpenSim, and it was released in January of 2007. So in a sense, free, open-source, decentralised Second Life has been around for a good 16 years.

And 15 years ago, it turned from a bunch of separated walled gardens into a federation of grids when the #Hypergrid was introduced, allowing whole avatars to teleport from grid to grid, regardless of who owns which grid. OpenSim became the first network of interconnected, decentralised #VirtualWorlds.

As of size, by the way, Second Life was on the brink of running out of space earlier this decade. The Hypergrid alone has more than four times Second Life's landmass and practically infinite space for making more land, partly because each grid has more space, partly because anyone with a computer at home can run their own grid.

Not to mention that the OpenSim community regularly used the term #Metaverse more than a decade before "it was cool".

@Prokofy Not "Mastodon Instance Service" but "Mastodon instance/server" as in "'Mastodon instance' or 'Mastodon server'".

The idea behind the existence of various public Mastodon #instances or Mastodon #servers is not simply load balancing. It is to have people with similar interests (or people living in the same place, or people with similar fates etc.) to be able to gather in one common place and make it easier for them to create a community.

A Mastodon instance with a Second Life theme would have the advantage for Second Life users to find other Second Life users more easily. The list of users on the instance, if it's public, will be chock-full of Second Life people. The local timeline will be chock-full of Second Life people talking about Second Life. You don't have to search your home instance (or other instances even) for the hashtag #SecondLife to find people all across the #Fediverse. I mean, you're complaining about exactly this yourself.

By the way, there is already a Mastodon instance for #OpenSimulator users which was probably created because more and more of them end up in the Fediverse. So I can't see why someone shouldn't create one for Second Life. If #LindenLabs doesn't, maybe a user does. I mean, the #OpenSim instance isn't run by OpenSim core developer Ubit Umarov either, but by the guy who made the Quintonia add-ons for the Satyr Farm.