title: What does rb-fsevent do?
body: <p>Recently updated Ruby on OSX Lion from 1.8.7 to 1.9.3.  In the process I lost the Ruby Gems that were installed on 1.8.7 so attempted to reinstall them.  </p>
  
  <p>Came across the rb-fsevent Gem.  The docs say: </p>
  
  <blockquote>
    <p>FSEvents API with Signals catching (without RubyCocoa)</p>
  </blockquote>
  
  <p>What exactly does it do?</p>
  
  <p>None of the other Gems are dependent upon it. So I'm wondering whether I need to install it on 1.9.3?</p>