f90doc is an automatic documentation tool for Fortran 90 written in Perl by Erik Demaine. It generates pages of HTML documentation from Fortran 90 source. Functions, arguments, types, etc. will be listed and the corresponding documentation for each element is taken from comments prefixed with
!!. f90doc also understands some basic wiki-like formatting rules. f90doc is similar to javadoc, but does not require comments to be written in HTML.