Spiderviz will follow (spider) the links of a website, remembering which pages linked to which. It employs some simple optimizations to avoid visiting duplicate pages. When it is done, the graph can be rendered to a PDF or PNG.
The example above depicts an old website that had a newer design grafted onto it (poorly). The end result is two clearly distinct clusters of web pages (corresponding to the two versions of the web site), each representing separate but largely duplicated information.
This article was originally written June 1, 2013.