InstantDB is a 100% Java, Relational Database Management System
(RDBMS). Features supported include joins, transactions, triggers,
sub-selects, table aliasing and much, much more that you wouldn't
normally expect to find in a free RDBMS.
Since its launch in July 1997, InstantDB has been adopted by thousands
of internet and database developers around the world. It is small,
efficient, easy to install, and comes with lots of examples to help
get the novice developer started. InstantDB is accessed via its
own JDBC driver. By using standard SQL and Sun's JDBC API, InstantDB
ensures that your applications enjoy a high degree of portability.
Lutris Technologies purchased InstantDB in April of 2000. The intent
is to Open Source InstantDB in the near future, and create the most
popular Open Source Java RDBMS.