I love RethinkDB and this looks like a great idea for testing. A lite ReQL implementation (just satisfying the API requirements, with little to none performance tuning) in something like C, though, would be even better for embedding purposes. You know, the biggest selling point of SQLite isn't that it makes testing easy, but that it's easy to embed.<p>Single-binary tool with an embedded RethinkDB, syncing with a master instance when it's connected to the internet - one can dream.