For example, you could go to "web development" and it would show a hype graph for a new technology (e.g., polygon), and on another of say, web browser, you could see a graph showing Vivaldi as an emerging technology and Internet Explorer as superseded.
I haven't been able to ever find that site again! Hopefully some of you know it?
HN has has much discussion of such graphs, so you might want to check all these results: https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...