To the best of my knowledge (n.b.: I am not an expert, though I follow this field) there still aren't any direct competitors to the breadth of what FoundationDB can do and do well.

There is not

The speed and durability has gone unmatched. We can write millions of transactions per second w/ millions of reads w/o issue. We have never lost data or found data to be inconsistent.

Founder here. To the best of my knowledge, you are correct. ACID is getting thrown around a lot these days, and not being used in its strictest sense.

Google Spanner? Not OSS, but globally consistent, scalable, and extensively battle tested.

Spanner can do global consistency and (some?) transactions but I'm unaware of it being able to do the sort of layering Foundation can internally to expose largely different database forms on top of it. I have never used Spanner, though, so I'm open to being corrected.

What do you mean by “forms”? Spanner is also layered. The bottom layer is basically a key-value store. On top of that there’s a full blown SQL layer, which, BTW can work with hierarchical records as well as flat tables. Both support transactions and guarantee global consistency.

They may refer to FoundationDB layers. [1] While Spanner may be built on a key-value store equivalent, Google does not expose it as a service.

[1] https://apple.github.io/foundationdb/layer-concept.html

That's exactly what I was referring to. Thanks.

What competition do you feel FoundationDB has that has major traction and no lock-in?

cockroachdb and tidb/tikv? (= scalable key-value layer with transaction)