H2 is an SQL database engine written in Java (but also available as a native binary). JDBC and ODBC APIs are supported. Embedded and server modes are available. A Web console application is included. Clustering is supported.

Changes

A new Console starter application has been implemented. Views support has been partially reimplemented. The data type CHAR is now fully supported. Linked tables can now emit UPDATE statements. Two functions are supported: LEAST and GREATEST. Many bugs have been fixed, for example in the Console, when using views, linked tables, JDBC API, and the CSV tool.

URL: H2 Database Engine