Web annotation tools like Genius and Hypothesis let you add notes to any page on the internet. Will they become tools for serious discourse, or end up as a mostly ignored layer of digital graffiti?

Such results suggest that annotation could become a powerful force in fact-checking. But annotation has been around for quite some time, pre-dating the web for some time.

Maha Bali shares her experience learning about Hypothes.is for web annotation and how she plans to use her favorite feature: public annotation ...

We’ve talked about Google SideWiki and other methods for “Writing in the Internet’s Margins”, but what about some of the other web annotation services out there? This post talks about ...

Female bloggers have a long, sordid history of harassment on the Web— Gamergate is just the tip of the iceberg —and while Genius-enabled annotations could theoretically bring a larger audience ...

Google's Martin Splitt introduces the concept of Centerpiece Annotation and how different parts of a web page are analyzed and weighted ...

Yet another web annotation service is launching today. WebNotes is releasing virtual highlighting and sticky-note tools designed to help people track and annotate online content. The tools let ...

Layers.com is a soon to launch Web Annotation service. Another one? Yes, another one. There have been countless efforts to create a usable Web Annotation service. Diigo is one, Fleck is one (our ...

Reframe It says Google's Sidewiki service is too close to its own Web annotation service for comfort. Reframe It CEO Bobby Fishkin argues that Sidewiki's features mimic Reframe It's right down to ...

New Zealand startup Notable PDF has created an online tool to help users collaborate and annotate PDFs online.

Annotation service now has a professional version for users who want to mark up PDFs along with normal Web pages.

Annotations come in all shapes and sizes depending on the artifact and the intent of the document. People are probably most familiar with wireframe annotations, where the author calls out areas of ...