title: How to highlight the differences between subsequent lines in a file?
body: <p>I do a lot of urgent analysis of large logfile analysis. Often this will require tailing a log and looking for changes.</p>
  
  <p>I'm keen to have a solution that will highlight these changes to make it easier for the eye to track. </p>
  
  <p>I have investigated tools and there doesn't appear to be anything out there that does what I am looking for. I've written some scripts in Perl that do it roughly, but I would like a more complete solution. </p>
  
  <p>Can anyone recommend a tool for this?</p>