From Seo Wiki - Search Engine Optimization and Programming Languages
Mocha is a Java decompiler, which allows programmers to translate a program's bytecode into source code. Although the source code produced by Mocha is seldom identical to the original source code (comments, for instance, are lost), it is often surprisingly close.
A beta version of Mocha was released in 1996, by Dutch developer Hanpeter van Vliet, alongside an obfuscator named Crema. A controversy erupted and he temporarily withdrew Mocha from public distribution. As of 2009 the program is still available for distribution, and may be used freely as long as it is not modified. Borland's JBuilder includes a decompiler based on Mocha.