There is a full list of tools you might be interested available here: http://www.makeuseof.com/tag/web-annotation-tools-research-annotate-collaborate/
Posts Tagged ‘collaborate’
web application – What is your suggestion for creating & sharing comments and/or highlighted texts of a web page? – Web Applications
In case you never came across any ‘Web Annotation’ service before, than basically what it is, is a bookmarking tool (usually in the form of browser addon or bookmarklet) that allows users to annotate (add sticky notes, highlights, etc.) any desired webpage and store it online.