FIREBIRD
Firebird
Firebird is an open source SQL relational database management system that runs on Linux, Windows, and a variety of Unix. The database forked from Borland's open source edition of InterBase in 2000, but since Firebird 1.5 the code has been largely rewritten.The above text is a snippet from Wikipedia: Firebird (database server)
and as such is available under the Creative Commons Attribution/Share-Alike License.