"Annotea is a LEAD (Live Early Adoption and Demonstration) project enhancing the W3C collaboration environment with shared annotations. 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."

Annotea project