Doxygen is a free, multiplatform (Linux, Windows, Mac, ...) tool for easy generation of program manuals. It supports popular programming languages such as C++, C, C#, PHP, Java, Python, Fortran. Doxygen also supports the hardware description language VHDL. It can generate an on-line documentation browser (in HTML) and/or an off-line reference manual (in LaTeX) from a set of documented source files. There is also support for generating output in RTF (MS-Word), PostScript, hyperlinked PDF, compressed HTML, and Unix man pages. The documentation is extracted directly from the sources, which makes it much easier to keep the documentation consistent with the source code.
Embedded Inventor. Complete Guide On Using Doxygen To Document C Source Code..!!