It’s diverged quite a bit from the original:

    <form method="GET" action="/search">
      ...
      
      <center>
        Search the web using Google!
        <br>
        
        <input type="text" name="query" value="" size="40">
        <br>
        
        <select name="num">
          <option value="10" selected>10 results
          <option value="30">30 results
          <option value="100">100 results
        </select>
        <input type="submit" value="Google Search">
        <input type="submit" name="sa" value="I'm feeling lucky">
        <br>
        
        <i>Index contains ~25 million pages (soon to be much bigger)</i>
      </center>
      
      ...
    </form>

When did they change the "query" to q?