HyperXtremeSQL™ is a super-fast SQL database engine written in Java. It support SQL and JDBC in J2SE and J2EE contexts.
HyperXtremeSQL is fully compatible with the open-source HSQLDB engine at the application level and can replace the HSQLDB jar in an existing application with no change to the Java code or SQL queries. HyperXtremeSQL is built around a new indexing and persistence core that replaces HSQLDB core classes. The HyperXtreme core breaks new ground as it lowers the code footprint, reduces memory use and at the same time significantly speeds up query performance in all areas of SQL, all modes of database operation and all sizes of database.
HyperXtremeSQL is lightweight, featuring full embedded functionality at less than 350K jar size and full client-server functionality at less than 400K.