Hey guys and gals<p>On any gitbooks (for example: https://codegangsta.gitbooks.io/building-web-apps-with-go/content/go_makes_things_simple/index.html). When you hover over a paragraph a little ' + ' icon comes up allowing yo to leave a comment on that specific paragraph<p>What is the feature called and is there a JS library or something for it?<p>Thanks in advance :)
One way to investigate this would be using the developer tools in your browser. Usually the F12 key brings them up in the major browsers.<p>One of the great things about javascript and the web is that it is possible to 'dissassemble' most code at least partially.<p>Good luck.