You can download HSQLDB at
hsqldb.sourceforge.net.
But I reconized that 1.7.2 does not accept the CREATE TABLE-statement, so you better try the version 1.7.1.
Enter the driver and url when asked or modify xlearning.properties (will be created if it does not exists already).
Example:
db.url=jdbc:hsqldb:file:xlearningdb
db.driver=org.hsqldb.jdbcDriver
db.username=sa
(note: make sure the driver is in the classpath, for example you just put the jar connector in the ext directory of your JVM)
However, I am not sure this is currently working probably because my harddisk gave me a headache again and I cannot test it well anymore.