zz-parent
· de.unkrig.zz - A set of command-line tools and ANT tasks that handle not only directories and files, but also archive and compressed files, and even nested archive files.
Download JD-GUI to open JAR file and explore Java source code file (.class .java)
Click menu "File → Open File..." or just drag-and-drop the JAR file in the JD-GUI window zz-parent-1.3.10.jar file.
Once you open a JAR file, all the java classes in the JAR file will be displayed.