Ranked in these QuestionsQuestion Ranking
Pro Open Source
Hypothesis is completely free and open source, its source code is hosted in GitHub.
Pro Chrome and Firefox browser extensions
Has browser extensions for both Chrome and Firefox, which makes the job of annotating web pages even easier.
Pro Private or Public
You can work in private groups and then publish, keep annotations private, or make it public from scratch.
Pro Everything can be searched through
Searchable stream of annotations, replies, and email notifications.