I been maintaining a little hosts project for blocking ads and trackers [0]. I've casually noticed over the years that a lot of the lists out there combine other people's lists - some are more upfront about it then others. That got me thinking, who was the first list to block domain X? That is where this website comes in.
A lot of popular block lists are hosted on GitHub, so that made it really easy to clone the repo and do a full history import of the project. I made a little script that could walk the git history and generate a JSON file containing all the unique versions to import [1]. The oldest lists from Steven Black's popular hosts project: April 2012 [2]. Other lists are harder to find history on, so they just go back as far as this project does.
As a test to watch domains from one list get consumed by other lists, I added a fake domain to my list 'developer-dan-list.clksite.com'. This root domain is particularly useful since it is a wildcard and will have a valid DNS response to any subdomain. As expected, I saw it get added to multiple lists in the following days.
[0] https://www.github.developerdan.com/hosts/
[1] https://github.com/blocklist-tools/github-history-generator
[2] https://github.com/StevenBlack/hosts
