This site provides a user interface to extract source code from .class and .jar ‘binary’ files. Until recently, you needed to use a Java decompiler and all of them were either unstable, obsolete, unfinished, or in the best case all of the above. The obsoleteness was typically proved by the fact that they can only decompile JDK 1.3 bytecode. But recently, a new wave of decompilers has forayed onto the market: Procyon, CFR, JD, Fernflower, Krakatau, Candle.