Many of the values in the MANIFEST.MF can be accessed programmatically
without having to find and/or open the jar file itself.

The class java.lang.Package provides access to the ImplementationTitle,
ImplementationVendor, ImplementationVersion, SpecificationTitle,
SpecificationVendor and the SpecificationVersion.

http://stackoverflow.com/questions/2198525/can-values-defined-in-manifest-mf-be-accessed-programmatically