HSQLDB

I recently had the opportunity to try out HSQLDB, a SQL relational database engine written in Java. I must say, I was thoroughly impressed with its features and capabilities.

With its JDBC driver and support for a rich subset of ANSI-92 SQL, as well as SQL 99 and 2003 enhancements, HSQLDB proved to be a valuable tool. Its size is also noteworthy - at less than 100k for one version for applets, it is small and fast.

HSQLDB offers both in-memory and disk-based tables, which supports both embedded and server modes. And, with its plethora of tools such as a minimal web server, in-memory query and management tools that can be run as applets, and a number of demonstration examples, HSQLDB is an all-around fantastic product for anyone in need of a reliable and stable persistence engine and database.

In fact, HSQLDB is already being utilized in many Open Source Software projects and even in commercial projects and products, making it a trusted and well-known name in the industry.

Overall, HSQLDB's small size, ability to execute completely in memory, flexibility, and speed make it a top contender in the software market. I highly recommend giving it a try for any database needs.