"Doxygen is the de facto standard tool for generating documentation from annotated C++ sources, but it also supports other popular programming languages such as C, Objective-C, C#, PHP, Java, Python, IDL (Corba, Microsoft, and UNO/OpenOffice flavors), Fortran, VHDL, Tcl, and to some extent D."
http://www.stack.nl/~dimitri/doxygen/It is open source, there not an updated version for OS/2, and the GUI tool for OS/2 seems to only run on X11.
So I tried on Windows first and made a quick and dirty report from the XWorkplace code.
I really liked what the tool generated.