Eclipse Modeling: The CDO Model Repository 4.0 integrates with several NoSQL databases such as Objectivity/DB, MongoDB, and db4o. LINK
Category: Object Databases – Free Software
The Griffon db4o plugin enables lightweight access to database functionality using db4o. LINK
Pieter van Zyl and Espresso Research Group. OO7J is a Java version of the original OO7 benchmark (written in C++) from Mike Carey, David DeWitt and Jeff Naughton = Univ Wisconsin-Madison. The original benchmark...
Intersystems Download Caché eXTreme for Java (Registration required): provides an API to store and retrieve structured data over JDBC (JDBC over JNI), unstructured data and Java Objects. LINK.
db4objects. Open source object database for Java and .NET. Free GPL download includes an interactive tutorial to get started quickly. LINK
Intersystems A free, fully-functional, non-expiring, single-user version of Caché. LINK
Peter Baumann, Jacobs University An open-source array DBMS with an OQL-style query language and ODMG-conformant C++ and Java APIs for retrieving and manipulating multi-dimensional arrays (rasters) of unlimited size. LINK
Versant Versant Object Database: for complex data storage in C++ and Java. Versant FastObjects .NET: for .NET applications with complex object models LINK (registration required)