• Google Sites: diiga example
  in Education > MSU > ENG 674 with diiga eng674 google_sites social_annotation web_2.0
• Social Annotation
  Seamless Integration of Social Bookmarking, Web Highlighter, Sticky-Note & Clipping
  Diigo is a powerful research tool and a knowledge-sharing community
  in Public bookmarks with research social_annotation web_2.0 web_apps by 79 users

social_annotation from all users