This is the best solution I've heard so far. Any server could have their own Technology group. Using Federation, anyone from anywhere could subscribe to each of them. Or, instead of subbing to each of them you just sub to the !tech tag, and you automatically get content from all of them. When you start a community you apply any tag you want to be included in.

To me, the instance should be mostly invisible/seamless. Subbing to tags instead of instance communities puts the focus on the content rather than where the content came from. Tags would make one large meta community that simulates how that other site feels, but with the option to still subscribe to a specific community if you ended up liking it more.

Say for instance one of the !tech groups ends up with really good content and discussions and the other smaller ones end up with a lot of duplicates and low quality comments. You'd easily be able to see which one you'd want to sub to directly. In this way tags would make community discovery much easier. Instead of having to seek out 10 different groups on 10 different instances, you sub to a general interest tag and either that works well enough or you discover the one you like the most and sub to that one directly.

I am glad I read through the comments first because this is what I was going to suggest. Because you may not want to see all the comms post because some are more friendly then others and some may only post in an language you don't understand. With tags you can discover all the comms or even create one feed with comms like #tech #English #Japan you never even sub to them unless you need to manage those particular comms/posts with those tags.

We could make it possible to group tags so there are multiple feeds and you can pick to see all feeds or one or many that you have created. It will be like groupings all of the comms/post you like together to one community but making it very personal because you may only care about tech in Japan but you want to have all the news from your country and maybe do not care what country memes comes from. But if you really want to mange them by comms then that should be an option to. So the tags will be a tool to discovering comms instead then.

@Stardust this is a great approach I see suggested often. A 2-dimensional identity for a community; one through tags, another through names/policies/wikis/sidebar info. Like, you might have users see all the time and identify with from a specific sub, and also have labeled/mechanical community interaction with much less familiar people in the tags if that makes any sense. Kind of like how Reddit would recommend related posts from adjacent subs I suppose, but this would be on a user-generated level.

@TerryMathews