> Blacksky is literally the only such example of alternative infrastructure that I know of

That doesn't mean other places aren't doing so. As an example - here's a list of all the relays that mirror the ATProto network: https://atproto.at/relays

There's 16 relays by my account, of varying sizes. Of course, you don't have to query a relay - you can look at the Personal Data Servers (PDSes) directly.

Speaking of - there are just over 3000 PDSes: https://blue.mackuba.eu/directory/pdses

Each of these PDSes hosts one or more accounts, and you can self-host your PDS to truly own your data up and down the stack.

There's also oodles of different applications, of which Bluesky is just one. There's:

* Germ (encrypted DMs, Signal competitor)

* Leaflet (blogs, Substack/Medium competitor)

* Semble (link collection/sharing)

* BeaconBits (location-based social media, like FourSquare)

* SkyReader (Google Reader)

* Keytrace (cryptographic identity proofs)

* Smoke Signal (social events)

* Teal.fm (Last.fm)

* Goals.garden (goal/habit tracking/accountability)

* Tangled (GitHub)

* Sifa (LinkedIn)

* BookHive (Goodreads)

* Streamplace (Twitch)

* Spark (Instagram)

* Grain (also Instagram)

* Popfeed (Trakt)

* And more, like the TikTok clone I can't remember the name of, some more blogging platforms, a (fairly dead) Hackernews clone, some games, etc.

That isn't even mentioning all the Bluesky clones like Blacksky, Eurosky, Northsky, and W.

Each of these shares the same account - the account on your PDS, which you can self-host on any computer with an internet connection. I run mine alongside my smarthome server. Because they share an account, they interop - I can subscribe to a blog on Leaflet and have it show up in my Bluesky feed.

These services can fetch data from your PDS directly, or they can look at the Relay and get the full view of the network - but frequently, they don't need to.

Bluesky went down a couple months ago and many of these services were all perfectly usable, because they used the protocol but not any infra provided by Bluesky itself. The people who couldn't access the network were the ones who relied on Bluesky to host their accounts - which is a majority of the network, sure, but in the same way that Mastodon.social is a good chunk of Mastodon's network. I was able to use Blacksky to post onto Bluesky while Bluesky was down, because I was self-hosted.

Now both Eurosky and W have launched; Eurosky is aiming to be fully independent this summer and I _think_ that W already is? W's a bit more closed-off than most of the other projects I named, going directly after Twitter-as-it-is-now and not Twitter-as-it-was (hence why they chose W to compete with X).