Javadoc is a documentation generator from Sun Microsystems for generating API documentation in HTML format from Java source code. The "doc comments" format used by Javadoc is the de facto industry standard for documenting Java classes. Some IDEs , such as Netbeans and Eclipse will automatically generate Javadoc HTML. Many file editors will assist the user in producing Javadoc source and will use the Javadoc info as internal references for the programmer. Javadoc also provides an API for creating doclets and taglets, which allows you to analyze the structure of a Java application. This is how JDiff can generate reports of what changed between two versions of an API. (via Wikipedia)