The move
ZUV has been completely integrated into Mustangproject and the development will continue there, so have a look on https://www.mustangproject.org/ if there is anything new: No more releases will be added here. This way you can also use it as a library, or if you prefer the command line application, use java -jar Mustang-CLI-2.0.0.jar --action=validate --source=factur-x.pdf .
New
ZUV/Mustang now also supports validating XRechnung 2.0, and throws notices if an EN16931-file does not comply to the XRechnung, unless of course started with --no-notices.