What really needs contributors are the streams repository and probably also Forte. They're very powerful, they're highly advanced, they're secure and resilient, they're basically what the whole Fediverse should be like, and they can blow not only Mastodon out of the water, but also Pleroma, Misskey and all their forks. But they only have half a maintainer at best because their creator has officially retired.

Allow me to elaborate:

These are the youngest offspring of a family of roughly Facebook-like Fediverse server applications created by Mike Macgirvin. They started in 2010 with Mistpark, later Friendika, now known as Friendica. The focus has never been on aping the UI/UX of something commercial and centralised, like Lemmy apes Reddit, but to create a replacement that's actually better. Toss out stuff that sucks, add features that could be useful like full-blown blogging capability, including blogging-level text formatting, and a built-in file space with its own file manager.

The next in the family was a 2012 Friendica fork originally named Red that introduced the concept of nomadic identity. As of now, and outside developer instances, nomadic identity is a feature exclusive to Mike's creations. Red became the Red Matrix, and in 2015, it was renamed and redesigned into Hubzilla, a "decentralised social CMS" and the Fediverse's biggest feature monster.

What followed was a whole bunch of forks, mostly development forks, only one of which was officially declared stable. This led to the creation of the streams repository in October, 2021. It's a fork of a fork of three forks of a fork (of a fork?) of Hubzilla, but the first fork already lost many of Hubzilla's extra features and a lot of Hubzilla's connectivity.

The streams repository contains a Fediverse server application that is officially and intentionally nameless and brandless ("streams" is the name of the repository, not the name of the application), that is not a product, that is not a project, and that is just as intentionally released into the public domain, save for 3rd-party contributions inherited from Hubzilla that are under various free licenses.

While (streams), as it is colloquially called, may not have Hubzilla's wealth of features, it has to be one of the two most advanced pieces of Fediverse software out there. With its permissions system that is even improved over Hubzilla's, hardly anything can match it in safety, security and privacy. On top comes resilience through nomadic identity. Also, (streams) is more adapted to a Fediverse that's driven by ActivityPub and dominated by Mastodon whereas Hubzilla seems stuck in the mid-2010s in some regards.

At this point, it should be mentioned that while Friendica, Hubzilla and (streams) can communicate through ActivityPub, none of them is based on it. AFAIK, Friendica is still based on its own protocol, DFRN, which is used by nothing else. Hubzilla is based on an older version of the Nomad protocol known as Zot6. (streams) is based on the current version of Nomad and also understands Zot6 for the best possible connectivity with Hubzilla.

So one of the latest development goals for the streams repository was the introduction of nomadic identity via ActivityPub, a concept that first appeared in 2023. I'm not sure how far this has been developed. But Mike created a new (streams) fork named Forte in August this year which had all support for non-ActivityPub protocols removed, probably also to cut down the maze of ID for everything which blew up on (streams) when support for FEP-ef61 was pushed to the release branch in July. Also, Forte has a name, it has a brand, it has a license, it has fully functional nodeinfo, and it is a project. Otherwise, Forte is identical to (streams).

Currently, there is only one Forte instance with one user, and that's Mike's private channel which mostly only his friends know about. Forte can be considered very experimental at this point, at least until Mike declares it ready for prime-time. After all, Forte has to handle nomadic identity via ActivityPub which, so far, is only proven to work under developer lab conditions at best.

However, there isn't much going on in terms of development. After the hassle that was getting malfunctioning (streams) back on track this summer, Mike officially retired from Fediverse development at the turn from August to September. He hasn't quit entirely, but he only works on (streams) and Forte sparsely. At the same time, the (streams) community was and still is too small to have a willing and able developer amongst themselves, and Forte has no community.

According to Mike, Forte could (and should) be "the Fediverse of 2030". It only needs more people working on it.

Large corporations tend to put profit over morality and the legal machinery to even try to bring them back into line moves slowly (and expensively) when they do so.

If your Mastodon posts are visible from Threads, Threads may "accidentally" determine that that content was posted by one of their own accounts covered by their own Terms of Service and so choose to do something with it that the Mastodon user did not agree to.

Now consider that Meta, Threads' parent company has put things in both its Facebook and Instagram Terms of Service that say they can do whatever they like with content posted on their platforms, including feed it to any "AI" as they see fit.

And what about responses to Threads posts from the Fediverse? What rights do Meta have to those? I'm sure you can imagine what Meta thinks, or might allow themselves to think, in that regard.

Presumably you can now understand why some Mastodon instances (and other Fediverse places) don't want anything to do with Meta or their products and wish to protect their users from that abuse.

You might argue that it will happen anyway, but in their view, any protection is better than none.

And the great thing about the Fediverse is that you're welcome to find, or even run, an instance that leaves itself open to such "interoperability".