It was dead for a while and has been resurrected but not much activity apparently.

I was surprised to see an update but am glad there is. Meanwhile Redis seems to do Rethink's job but also act as a cache or more advanced distributed scenarios use some event queue. But classic and nosql databases have caught up as well and provide change streams/notificatons.

Last time I checked (many years ago) performance of RethinkDB compared to the classic databases wasn't quite there.