I've seen this a few times, once as a firefox addon which is no longer available by the looks of it.[1]
I'm pretty sure Mosaic tried a similar thing about 20 years ago.
The other time I saw it was in the form of a DAG which appeared in a panel above the address bar which could be selectively hidden. The graphics were crude as I think it was rendered in GraphViz. I can't for the life of me remember where I saw this - tried searching for it again with no look. Pretty sure it was in a video demonstrating an experimental browser, but I'm lost as to which. (Maybe I dreamt it)
I'm pretty sure Mosaic tried a similar thing about 20 years ago.
The other time I saw it was in the form of a DAG which appeared in a panel above the address bar which could be selectively hidden. The graphics were crude as I think it was rendered in GraphViz. I can't for the life of me remember where I saw this - tried searching for it again with no look. Pretty sure it was in a video demonstrating an experimental browser, but I'm lost as to which. (Maybe I dreamt it)
I just found another while searching too.[2]
[1]:http://www.technotraits.com/2009/09/browse-firefox-history-i...
[2]:https://addons.mozilla.org/en-US/firefox/addon/fromwheretowh...