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.
Dr. Geo is an interactive geometry program that is distributed as a universal portable application. It allows one to create a geometric sketch and manipulate it according to its constraints. It is usable at home or at school, in primary or secondary education. It is simple and effective with extended features including scripting and programming.