MongoDB is a document-oriented, NoSQL database that leverages JSON-style documents with dynamic schemas (known as BSON), rather than a table-based RDBMS structure. MongoDB’s code is open-source, although its parent company MongoDB Inc. offers a subscription-based enterprise version that includes consulting, training, and management services. MongoDB has a comprehensive, flexible feature set that handles such tasks as rich, document-based queries; full index support; mirroring across LANs and WANs for high availability and replication capabilities; auto-sharding, which lets developers scale horizontally without undermining functionality; Map/Reduce for flexible aggregation and data processing; and GridFS, which stores files of varying sizes without complicating data stacks. Many organizations use MongoDB as their backend storage framework, including Craigslist, SourceForge, Viacom, SAP (for its PaaS), and many others. Even CERN (European Council for Nuclear Research) uses MongoDB as its primary back-end for its Large Hadron Collider’s data aggregation system!