ShiftSpace

• Description: Web annotation plug-in for Firefox. Allows comments and HTML code substitution.
  • wikipedia:ShiftSpace
• Features: Comments, Browser plugin interface, client page alteration
• Timeline: 2006 (released) - present? (last updated may 2011)
• Authors: D.Phiffer et M.Zer-Aviv
• Academic publications (I don't know if I would call that peer reviewed)
• Sites
  • http://www.shiftspace.org/
  • https://github.com/ShiftSpace/shiftspace
  • http://code.google.com/p/shiftspace/

Comments

• Defines the concept of "trail" (I have not clear if it refers to a sequence of navigation)
• Uses terms like "augmented browsing" and "meta layer"
• Actions like image substitution, or HTML source modification (though limited to client on request) might be considered like vandalising.
• Gives credit to extint alternatives (SideWiki), but says nothing about the previous and ongoing work in the W3C