It seems dbDeploy, migrate4j and MIGRATEdb are abandoned (last release for migrade4j was in 2008, and for dbdeploy in 2009 and MIGRATEdb in 2014)
I just had a brief look at MIGRATEdb and the fact that each change needs to for itself it has already been applied somehow defeats the purpose of such a tool.
The only true contender I know of today, is Flyway which only(?) supports custom SQL scripts.
I still prefer the XML format because it can be used for DBMS independent migrations and allows for some automated analysis of the migrations which is really hard to do with SQL scripts (e.g. we have a little tool that parses the XML and then checks if certain naming conventions are following if each table has a primary key and so on).
It also makes generating a changelogs easier. We also have a set of macros for Toad Data Modeler that allow us to generate the Liquibase Changeset directly from there - in a DBMS independent manner. We even had a set of XLST scripts that would convert the XML of a freeware modelling tool into a Liquibase ChangeLog