45 Hypothes.is
Hypothes.is is a web annotation tool that allows collaboration between authors and editors, personal note taking and annotation, and engagement with readers. It can also be used as a teaching tool with students.
While the tool is available as a browser extension that can be used on any webpage, Pressbooks allows building its capabilities into the pages of your webbook.
While Hypothes.is is automatically enabled in Wheaton’s OpenPress, for more information about using the tool in Pressbooks see Enable Annotation with Hypothes.is in the Pressbooks User Guide.