Web Annotation Discovery от Gerben

This browser extension implements the Web Annotation Discovery mechanism, enabling you to discover annotations and subscribe to annotation ‘feeds’ while browsing the web; then view the collected annotations on other pages you visit.

It also lets you create annotations yourself, and store/publish them on an annotation collection, so that other people view the notes you take on web pages.

Status

Minimum viable product, or primarily a proof-of-concept: This software demonstrates a mechanism for web annotation in practice, enabling people to try it out and hopefully move forward with the idea.

The software can be used for collaborative annotation, but be prepared for possible technical glitches (including data loss or leakage), mediocre user experience, and awful interface design.