Social Annotation: Diigo
After writing about online annotation, I received an invite to diigo, a new social web page annotation service. Diigo seems like a pretty cool idea, although the beta, at least, is hampered by some of the same fundamental issues encountered by all online annotation systems that I’ve seen. Diigo allows you to bookmark pages, highlight and annotate portions of pages, and share these content items with your friends, or the whole world, via feeds and tags. Diigo works via a Firefox, Flock (not surprising, as it comes from the same base as Firefox), or IE plugin. Unfortunately, the plugin is not available for Safari yet. With the plugin installed, you can highlight portions of a page’s text and leave annotations. Additionally, you can choose to view comments and annotations left by your friends, or the Internet as a whole.
The hard thing about web page annotation is figuring out how to lock a highlight or annotation to a specific place on a web page. Especially with dynamically generated pages, the content can change often, so how do you know where to put the annotation? I was excited to see how diigo handled this issue, and they seem to have taken the textual route, analyzing the page’s source via JavaScript and looking for text that matches what was originally annotated. This works when the annotated text is unique, but fails if you happen to annotate text the recurs on the page. However, this still works reasonably well. (If you’re interested, you can grab their plugin and unzip the .jar file to see how some of this stuff works. The interesting text selection code is in the core.js file.) I don’t know how to get around the annotation problem, but will keep an eye on diigo as they continue to refine their beta. Perhaps they will think of something that I haven’t.
Solution Watch and TechCrunch already wrote about Diigo.