Valentina is cross-platform SQL and non-SQL columnar database that allows development of client-server [Web] solutions and applications with an embedded local database using the same sources. Valentina DB provides an Object-Relational model, but you can also mix Relational and Extended Navigational. It introduces a revolutionary model abstraction "Link" that greatly simplifies db schema, and therefore simplifies SQL queries. It supports disk and in-memory databases, and field types including Bit, BLOB, Pictures, and Enum. It provides advanced features such as triggers, views, stored procedures, regular expressions, XML, full-text search, and calculated fields. It exists as Valentina Server, Valentina Studio, and a set of Valentina ADKs for all major programming languages.
db4o is an object database for Java and all .NET environments. Its features include ACID transactions, automatic class schema recognition, query-by-example, a S.O.D.A. object querying API, native queries, LINQ support on .NET, callback methods, memory files, cascade-on-delete, multi-threaded access, and Java Webstart and servlet support.
Spring is a lightweight Java/J2EE application framework based on code published in "Expert One-on-One J2EE Design and Development" by Rod Johnson. It includes powerful JavaBeans-based configuration management applying Inversion-of-Control principles, a generic abstraction layer for transaction management allowing for pluggable transaction managers, a JDBC abstraction layer, integration with Hibernate, JDO, Apache OJB, and iBATIS SQL Maps, AOP functionality, and a flexible MVC Web application framework with multiple view technologies. There is also a .NET port available.
ProviderFactory is an assembly for the .NET framework that provides a layer of abstraction for ADO.NET data providers. This allows programs to be developed in a way that allows for transparent database access to different ADO.NET data providers without having to change code or recompile.
Bugzproxy is a C# client library for the upcoming Bugzilla Bugtracker WebService interface (part of Bugzilla 3.0). It provides an OO access to a Bugzilla server. The aim of Bugzproxy is to allow easy building of various clients that facilitate the integration of Bugzilla into the various C# tool chains. As the project's aim is to provide an efficient and intuitive OO API, the API probably will change in future revisions.