RethinkDB is not offline first. It runs queries on the server-side, not on the client. There is horizonDB which can replicate with RethinkDB but the project is dead with no commits since the rethinkdb company gave up.

So I was one of the developers of RethinkDB's Horizon, and I'm really glad to see someone take the database change stream to RxJS concept to its logical conclusion.

This project looks really awesome, and very much has the shape we wished Horizon could have turned into

Because rethinkdb development has ceased? Last release was in 2017.

Is there still maintenance?

Why not maintain it rather than writing something new? Open source is frustrating

The community has taken it over as far as I know. Looking at the github there appears to be some active development still. https://github.com/rethinkdb/rethinkdb

"Is RethinkDB dead?"

https://github.com/rethinkdb/rethinkdb/issues/6747#issuecomm...

TLDR: They are hoping to announce a revival in the near future.