But unlike Hypothes.is, the Genius code is not open-source, its service doesn't work on PDFs, and it is not working with the scholarly community.

A few websites today have inserted code that allows annotations to be made on their pages by default, including the blog platform Medium, the scholarly reference-management system F1000 Workspace and the news site Quartz. However, annotations are visible only to users on those sites. Other annotation services, such as A.nnotate or Google Docs, require users to upload documents to cloud-computing servers to make shared annotations and comments on them.