title: Blanket.js vs Istanbul-js vs JSCover
body: <p>I am trying to decide on a JS test code coverage tool but cannot see clearly the differences between them. The top hits in Google are blanket.js, istanbul-js and JSCover. </p>
  
  <p>Can anyone offer any information on the key differences between them and advantages/disadvantages?</p>
  
  <p>Are there any other useful ones out there?</p>