db4o 6.1

db4o is designed to be a simple, easy-to-use, and fast, native object database. Software developers using popular Java and .NET object-oriented frameworks know that using object databases is a more natural way to get work done. Developers have three ways to storing and retrieving data: relational, non-native object and native object.
Relational databases, such as Oracle, IBMs DB2 and Microsofts SQL server, store data in a tabular, row-and-column metaphor. The organization of traditional data in a relational database is easy to understand. The concept took off and today most data is stored in relational databases.
However, as object-oriented models became popular, developers were spending time trying to map objects into a relational database. Today, developers are forced to rely on relational-to-object mappers, but this technology compromise adds a layer of complexity and degrades performance. It is best suited for organizations that rely on legacy data.
Non-native object databases came on to the market in the early 1990s with great fanfare. But their promise was largely unfulfilled. Developers found the technology expensive, complex and hard to use. The first native object databases had similar shortcomings.
db4o is based on new native object database technology. db4o offers .NET and Java developers the simplest and easiest way to store objects. db4o is the only native object database designed for both Java and .NET, supplied as one single programming library (Java: .jar /.NET: .dll) to be included with developer applications.
Main features:
- One line of code to store objects
- Native Java / .NET
- Class model == database schema
- Smooth production process
- Automatic schema versioning
- Query by example
- S.O.D.A. active queries
- 250kB footprint
- Saves more than 50% costs to develop your application
- Saves more than 50% time to release your application
- No need for training and administration
- Build lean, structured and manageable code
- Improve your software lifecycle with better refactorability and re-use
Enhancements:
- This release comes with an improved client/server protocol, which is now completely asynchronous and able to batch messages.
- Both changes reduce the number of client/server message round trips, and therefore improve client/server performance.