Nothing else does what vanadium does, especially at its sophistication level. I don't know if I'd use it in production yet unless you are willing to put in some engineering resources, but you're unlikely to find something else as well made elsewhere. This is the product of a very elite team... which means it's also very complicated to use.
This is the product of a very elite team... which means it's also very complicated to use.
That's an unfortunate assumption. Looking back at historic examples, the Windows API was complicated to use while the NeXTSTEP API wasn't. Is there any question which was created by an "elite team"?
Syncbase is the attempt to simplify it and abstract a lot of it. It's API is much more straightforward and is fairly easy to work with.
Part of the complexity is that it's solving like 15 major problems at the same time in an interconnected way. It's also solving them for people like google which means there are a lot of requirements for all the things it needs to do.
Because it does new things, in addition to old things in new ways, there's a steep learning curve for all of its concepts. I totally agree that doesn't mean it couldn't be more elegant and "simple," but the win32/nextstep analogy isn't fair as they were far more similar than vanadium is to anything else. Vanadium is like a hybrid of (to use existing concepts) dns/http/ssl/json/bluetooth/nosql/ntp/kerberos and more. When you put it all together there isn't a lot of existing references or cognitive frames to help you "get it" righ away.
The outcome I'm looking for is basically CRDT (or something very like it) using only BYO smartphone & laptop devices (acting as both the forwarding nodes and the application client), robust against nontechnical user mishap and patchy/absent Internet connectivity.
Hod @ Couchbase here. Depending on what you mean, I have to disagree. Are you talking about Vanadium Core, or Vanadium and Syncbase? From what I'm reading, Couchbase does significantly more than Syncbase. It supports many of the security features of Vanadium, although it doesn't have ACLs with things like proximity built-in.