TrueLicense
· TrueLicense is a commercial open source engine for license management on the Java Virtual Machine.
Due to its functional and modular design TrueLicense scales from simple to complex licensing schemas.
TrueLicense features various interfaces for managing free trial periods, subscriptions, multiple editions,
internationalization, privacy protection and more.
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 truelicense-3.2.0.jar file.
Once you open a JAR file, all the java classes in the JAR file will be displayed.