JD-GUI , A lightweight java decompiler

JD-GUI is a standalone graphical utility that displays Java source codes of “.class” or ".jar" files . You can browse the reconstructed source code with the JD-GUI for instant access to methods and fields. This is a free tool for non-commercial use. I can guarantee you it's fast and reliable tool. I have been using it for couple weeks now and I'm totally contented with it.

JD-GUI is free for non-commercial use. This means that JD-GUI shall not be included or embedded into commercial software products. Nevertheless, this project may be freely used for personal needs in a commercial or non-commercial environments.

JD-GUI is can be downloaded by visiting it's official site and is available for Windows, Linux and Mac platforms. 

Main Features

• JD-Core and JD-GUI are written in C++. This allows an extremely fast decompilation and a display.
• JD-Core does not require the Java runtime environment for its functioning, therefore no special setup is required.
• JD-Core works with most current compilers including the following:
  • jdk1.1.8
  • jdk1.3.1
  • jdk1.4.2
  • jdk1.5.0
  • jdk1.6.0
  • jdk1.7.0
  • jikes-1.22
  • harmony-jdk-r533500
  • Eclipse Java Compiler v_677_R32x, 3.2.1 release
  • jrockit90_150_06
• JD-Core supports the following new features of Java 5:
  • Annotations
  • Generics
  • Type “enum”
• JD-GUI supports Drag and Drop.
• JD-GUI supports JAR files.
• JD-GUI displays color coded Java source code.
• JD-GUI allows you to browse the “class” files hierarchy.
• JD-GUI displays “log” files, and allow you to decompile “class” files appearing in Java stack traces.
• JD-Core, JD-GUI and JD-Eclipse use the excellent cross-platform wxWidgets toolkit.