If you are interested in trying grdoc, you are welcome to upload a copy and try it. It is written using Perl, and installation amounts to simply editing grdoc and changing the $installdir variable and other things in the user option block (top of the code). We distribute the code as a .tar.gz file which is available via this hyperlink to grdoc.tar.gz. Note this file also contains grdoc.el, a set of elisp macros for inserting blocks into codes.
grdoc was written by Paul Walker, at the NCSA. It is minimally supported, in that we use it for source code documentation of the Cactus Code, so that we are happy to try and answer any questions, but it is not currently being further developed.