If you look at the commit dates you'll see that it has been a while since this library has been updated. Unfortunately it was never finished, but if you're looking for a non-Java library for parsing JVM class files, I'd recommend you checkout my latest project, jvm.js, which allows you to parse and perform static analysis on JVM class files. It's not feature-complete just yet, but is much further along than this project and holds a promising future.
This library is for parsing and manipulating Java classfiles similar to the Bytecode Engineering Library https://commons.apache.org/proper/commons-bcel/
This is for manipulating Java classfiles with ease and without having the overhead of the JVM.