Doxygen is a documentation generator tool that can extract code structure and documentation from source files written in C, C++, Java, Python and other languages. It shows relations between code elements like functions and classes through hyperlinks. Doxygen can generate documentation websites, inheritance diagrams and other diagrams. To use it, the user runs the Doxygen wizard, specifies the source code and output locations, selects diagrams to generate, and clicks start to generate documentation. The results can then be viewed through automatically generated class hierarchy diagrams, UML diagrams and other documentation.