Bytecode Viewer is a Java Bytecode Viewer, GUI Procyon Java Decompiler, GUI CFR Java Decompiler, GUI FernFlower Java Decompiler, GUI Jar-Jar, Hex Viewer, Code Searcher, Debugger and more. It's written completely in Java, and it's open sourced. It's currently being maintained and developed by Konloch There is also a plugin system that will allow you to interact with the loaded classfiles, for example you can write a String deobfuscator, a malicious code searcher, or something else you can think of. You can either use one of the pre-written plugins, or write your own. It supports groovy, python and ruby scripting. Once a plugin is activated, it will send a ClassNode ArrayList of every single class loaded in the file system to the execute function, this allows the user to handle it completely using ASM.