The most recent version of gnuclad and it's documentation can be downloaded at https://launchpad.net/gnuclad.
You can also file bugs and contact the developers there.
gnuclad has been written to facilitate progress of the GNU/Linux distro timeline project (GLDT).
Meanwhile it has become quite customisable and general application - for example in genealogy or visualisation of hierarchical structures - should be possible.
The documentation is distributed together with gnuclad and can be found in the 'doc' folder.
GNU/Linux distro timeline: http://futurist.se/gldt/
Stéphane List Development Timeline: http://slist.lilotux.net/prog/