I don’t know anything about Neptune, but a Fediverse-version of TikTok is Loops.video.

Well, it’s not a protocol, Subsonic is an app that became pretty famous in the MP3 era and had a nice API for which various clients were developed.

The source code was Open Source in the early days which was forked into e.g. AirSonic.

Both projects are dormant for a few years now. That’s why new ones have emerged that simulate the same API so all the client apps can still be used with them.

Ah, so alternative implementations. I’ve still got a license for the original Subsonic, but that hasn’t been updated in years by now.

Subsonic? Is this still a thing?

I have all my photos synced to iCloud and have Apple Photos running on my Mac with the option to “always download originals” enabled. Then, I run a daily backup of my Mac’s photo library to my NAS. For this, I’m using CCC at the moment but I’m planning to switch to restic.