It’s now possible to select the driver to use for embedded databases within Base thanks to the new selector:
The default database remains HSQLDB, however this change allows easy creation of new firebird based .odb files (mainly for testing purposes at the moment), whereas previously manual extraction and editing of the .odb file was necessary to create such a file. This also means that in future, once the default database can be changed to Firebird, it will still be possible to create HSQLDB files for compatibility with older version of LO/OO/etc.