Hypothesis[archived] is a project that offers an annotation layer on top of the web. It's something that I always wanted to see, and something that has been tried many times in the past. In fact, while signing up for Hypothesis today I discovered I already had an account from 2012!

I installed the unofficial Firefox extension[archived] and decided to give it a try. I like that you can use to annotate PDFs, which is something I've wanted in the past. I don't like that I can't self host my annotations and make them available through a decentralized protocol.

I'm also considering adding it to my weblog, so that people without the extension can see the public comments (and maybe annotations). I could just add their Javascript to my weblog[archived], but I want to have ownership of comments so I can preserve them. Looking at their API it seems that I can fetch all public annotations and comments for a given URL, so that might work.