title: What would be the equivalent of Win32 API in linux?
body: <p>I don't want to know if there is a one-to-one equivalence between API functions in windows and linux, neither want to know every API function.</p>
  
  <p>I just want to know this for two basic things:</p>
  
  <ol>
  <li>I want to understand why is Qt platform independent</li>
  <li>I want to know what API should I use in linux to port an application programmed with the Win32 API, or in other words, at Win32 API level.</li>
  </ol>
  
  <p>I know that this is not practical but I want to know this equivalence.</p>