"LiquiBase — available since 2006 — is an
open source, freely available tool for migrating from one database
version to another (see Resources). A handful of other open source
database-migration tools are on the scene as well, including
openDBcopy and dbdeploy. LiquiBase supports 10 database types,
including DB2, Apache Derby, MySQL, PostgreSQL, Oracle,
Microsoft® SQL Server, Sybase, and HSQL."