db4o (database for objects) is the open source object database, native to .NET.

db4o (database for objects) is the open source object database, native to .NET. Free software, available under the GPL and under a commercial license. Ideal for embedded use, e.g., in software running on mobile or medical devices, in packaged software, and for real-time systems. Key Features: - The One-Line-of-Code-Database (One line of code stores any object; Class model = object schema; Smooth production process) - Embeddable (Zero administration; Automatic schema versioning; 400 KB footprint) - Multiple platform support (Native to Java and .NET; Mobile, PCs and servers; Runs cross-platform) - Brings more OO to the database (Object-oriented replication; Native Queries; ObjectManager browser) Key Benefits: - Slashes 90% of cost to develop persistence - 10% faster to market with your application - Runs up to 44x faster than conventional systems - Deployable in large volumes without local administration - Build lean and truly object-oriented software - Build distributed, fully synchronized data architectures - Fewer errors, better refactorability and software longevity