&gt; Let&#x27;s start with the simplest one. Making the developer interface to the database a structured format instead of a textual query language was a clear win.<p>I think this is the most significant factor, by far. With Mongo it&#x27;s turtles (or at least Maps&#x2F;Hashes) all the way down, without a strange pseudo-english layer near the bottom that forces you to translate back and forth. For some devs that&#x27;s a big deal.<p>For the last while I&#x27;ve been experimenting with bringing the same feature to PostgreSQL (<a href="http:&#x2F;&#x2F;bedquiltdb.github.io" rel="nofollow">http:&#x2F;&#x2F;bedquiltdb.github.io</a>), turns out it&#x27;s very do-able, but I don&#x27;t have enough time to make it as featureful as it needs to be.