- Better performance and less memory consumption than v5.x
- Lazy queries, a new server-side cursor technology to boost client-server performance
- .NET API changes make db4o as native to .NET as it is to Java
- Documentation "2.0", WIKI-based reference documentation infrastructure
- Fast defragmentation makes it now faster to defrag your database files
- ObjectManager v6.0, a complete rewrite addressing many user requests
- db4o Replication System (dRS) v6.0 now supports delete object replication as well as better compatibility to more databases
The other major change with this release is broader open source licensing. Db40o comes in both a GPL and commerical version (similar to mySQL). Licensing has been changed for the open source version to allow compatibility with projects licensed under Apache, LGPL, BSD, EPL, and others.