title: What's the universal standard to get data from any blog?
body: <p>I want to extract data from various kinds of blogs and was going through various ways to do it:</p>
  
  <blockquote>
    <ol>
    <li>API which needs user authentication</li>
    <li>XML RPC(Don't know which all support it)</li>
    <li>RSS(Again, not sure which blogs support it and even if they do, how much can one get from RSS feeds.)</li>
    <li>Atom</li>
    </ol>
  </blockquote>
  
  <p>I know that this isn't a strictly programming related question but I went forward in asking this as there is heck lot of confusion as to what to use and which is better served?</p>
  
  <p>It would be nice to not use API with Authentication as you not only will have to tackle with varied implementations of Authentication, you also have to deal with varied API limits. </p>