Why are there so many NoSQL databases?
silentbicycle: The new non-relational databases have fairly different designs. For example, if your data set would fit entirely in memory (on one or a few servers), Redis would probably be a great choice. Their different strengths come out of the design choices that set them apart.A while ago, there were several different database query languages for relational databases, too. In interest of having a standard, they compromised on SQL. There are lots of version control systems, parsing frameworks, programming languages, etc., too. This isn't really unique to databases, they just get talked about more since there's so much buzz about hot new web development stuff.