Annotea

W3C Semantic Web Annotation Systems work.

• RDF-based

http://annotea.org/

http://en.wikipedia.org/wiki/Annotea

http://www.w3.org/2001/Annotea/

Doesn't look like much is happening.

By annotations we mean comments, notes, explanations, or other types of external remarks that can be attached to any Web document or a selected part of the document without actually needing to touch the document. When the user gets the document he or she can also load the annotations attached to it from a selected annotation server or several servers and see what his peer group thinks.

Seems to use X Pointer, which Sun has a patent on, though... agrees it will grant royalty-free licenses, under reasonable terms and conditions, and on a non-discriminatory basis, under Sun's essential patent claims to make, use, sell, offer for sale, or import implementations of X Pointer.

I'm not clear on how granular a target you can annotate (e.g. part of a page/message).

Protocol <http://www.annotea.org/Annotea/User/Annotea Protocol-20051226.html>

Code - http://www.w3.org/2001/Annotea/Projects

Clients

• http://sourceforge.net/projects/annotatio

• FireFox/Mozilla plugin http://annozilla.mozdev.org/