title: How to get data with JavaScript from another server?
body: <p>How can I make requests to other server(s) (i.e. get a page from any desired server) with a JavaScript within the user's browser? There are limitations in place to prevent this for methods like XMLHttpRequest, are there ways to bypass them or other methods?</p>
  
  <p>That is a general question, specifically I want to check a series of random websites and see if they contain a certain element, so I need the HTML content of a website without downloading any additional files; all that in a JavaScript file, <em>without any forwarding or proxy mechanism on a server</em>.</p>
  
  <p>(Note: one way is using Greasemonkey and its GM_xmlhttpRequest.)</p>