Syncthing?

There is also Borg but I think it doesn’t have the features you’re looking for such as incremental backups and two-way sync etc.

What’s wrong with GitLab?

This is a brand new project so I’m sure no apps are using this yet or even have plans to.

Yep, vectors. See https://github.com/onthegomap/planetiler

You mean how much faster downloading vector tiles are in comparison to raster tiles?

I think pre-rendering makes the biggest difference, rather than the type of tiles.

Also see Nexus Search (@science_nexus_bot) on Telegram.

Probably meant CSAM (child sexual abuse material) instead.