H2 is an SQL database engine written in Java that implements the JDBC API. Embedded, server, and clustering modes are available. A browser based console application is included. The database has strong security features. Disk based and in-memory databases and tables are supported.

Changes

JaQu (Java Query), a tool similar to LINQ (Language Integrated Query from Microsoft) is now included. Deadlocks are now detected. Compatibility with other databases such as Oracle or Apache Derby has been improved. Java methods can now be overloaded. It is no longer allowed to create columns with the data type 'null'. Opening large databases was sometimes very slow.

URL: H2 Database Engine