The aim of Java Decompiler project is to develop tools to decompile and analyze Java 5, and upper, “.class” files.
JD-Core is a freeware library that reconstructs Java source code from one or more “.class” files. JD-Core may be used to recover lost source code and explore the source of Java runtime libraries. New features of Java 5, such as annotations, generics or type “enum”, are supported. JD-GUI includes JD-Core library.
JD-GUI is a standalone graphical utility that displays Java source codes of “.class” files. You can browse the reconstructed source code with the JD-GUI for instant access to methods and fields.
JD-Core and JD-GUI are free for non-commercial use.