HSQLDB (HyperSQL Database) is a relational database engine written in Java. Version 2.4 offers many features and adheres closely to the latest SQL and JDBC 4 standards.
A set of HTML, PDF and text documents covering different aspects of HSQLDB and some of its utilities.
HyperSQL User Guide in HTML format.
HyperSQL User Guide in PDF format.
HyperSQL Utilities Guide in HTML format.
HyperSQL Utilities Guide in PDF format.
The JavaDoc for public classes, including the JDBC documentation.
Chronological list of changes and bug fixes since the release of version 2.0 changelist_2_0.txt
The license texts for the source and binaries, based on the BSD license. hsqldb_lic.txt is for sources developed entirely by the HSQL Development Group. hypersonic_lic.txt is for sources that contain code from the closed HypersonicSQL project.
Support for HyperSQL is available from http://hsqldb.org/support in various forms, including a mailing list and user forums. The web site features the latest bugfix versions of the software, FAQ and other useful resources.