MongoDB (from "humongous") is a scalable, high-performance, open source NoSQL database. Written in C++, MongoDB features:
JSON-style documents with dynamic schemas offer simplicity and power.
Index on any attribute, just like you're used to.
Mirror across LANs and WANs for scale and peace of mind.
Scale horizontally without compromising functionality.
Rich, document-based queries.
Atomic modifiers for contention-free performance.
Flexible aggregation and data processing.
Store files of any size without complicating your stack.
Enterprise class support, training, and consulting available.