FoundationDB https://www.foundationdb.org/ not only supports transactions, they are mandatory. They also go one step further and support atomic operations, which are especially killer.
What do you mean by this? There is only one “database” in FoundationDB terms. You can write transactions over the entire keyspace regardless of which machine the data is stored on.
There's not really a concept of "Database" in FDB. There is however a concept of key spaces, and "directories", which are basically the same, and these all support transactions.
