MongoDB (from "humongous") is a scalable, high-performance, open source, document-oriented database. Written in C++, MongoDB features: Document-oriented storage » JSON-style documents with dynamic schemas offer simplicity and power. Full Index Support » Index on any attribute, just like you're used to. Replication & High Availability » Mirror across LANs and WANs for scale and peace of mind. Auto-Sharding » Scale horizontally without compromising functionality. Querying » Rich, document-based queries. Fast In-Place Updates » Atomic modifiers for contention-free performance.