title: What are the differences between CosmoDB and DocumentDB
body: <p>As far as I can work out, CosmoDB has the ability to make Graph queries using the Gremlin query language. Apart from that the pricing, marketing etc. all seem the same. It seems strange that they came up with a new product to add Gremlin when they didn't do the same to add MongoDB support. What are the discernable differences between these two products?</p>