HSQLDB is Lightweight 100% Java SQL Database Engine. HSQLDB is Java developers' best choice for development, testing and deployment of database applications. HSQLDB (HyperSQL DataBase) is the leading SQL relational database engine written in Java. It has a JDBC driver and supports a rich subset of ANSI-92 SQL (BNF tree format) plus many SQL:2008 enhancements. It offers a small, fast database engine which offers both in-memory and disk-based tables and supports embedded and server modes. Additionally, it includes tools such as a minimal web server, in-memory query and management tools (can be run as applets) and a number of demonstration examples.
The product is currently being used as a database and persistence engine in many Open Source Software projects and even in commercial projects and products. In its current version it is extremely stable and reliable. It is best known for its small size, ability to execute completely in memory, its flexibility and speed.
