Objectstore
- Provider of object data management products for Java, C++ and XML-based applications. Products include ObjectStore, PSE Pro and RTEE. Objectstore is the standard example of a page-server architecture, featuring also multi-version concurrency control, auto
- http://www.objectstore.com

GemStone Systems
- Offers GemStone and GemFire, distributed shared-memory OODBs with caching and (relational) data integration for Java, C++, and Smalltalk.
- http://www.gemstone.com

InterSystems Cache
- A scalable, "post-relational" database with a multidimensional data and application server for distributed web applications. It offers a SQL interface, and bindings for C++, Java, ActiveX/VB, Delphi and CORBA.
- http://www.intersystems.com/

Matisse Software
- Offers Matisse an replicated ODBMS with server-side SQL2, a version-based transaction mechanism and on-line schema evolution. Data definition languages is UML, bindings for several programming languages exist. A free developer version is available.
- http://www.matisse.com

Versant Corporation
- The Versant Developer Suite is a distributed, replicated object-oriented database featuring online schema evolution, failover, asynchronous replication and SQL query capabilities. Multi language access from C++ and Java for several operating systems.
- http://www.versant.com/

Objectivity
- Distributed, object database, with support for declaratively described transaction logic, quorum-based read/writes and schema evolution. Bindings for C++, Java, Smalltalk, and SQL.
- http://www.objectivity.com/