title: which o.s. supports file custom extended attributes?
body: <p>I want to develop a cross-platform utility that works with custom or extended file attributes.</p>
  
  <p>Do you know which commonly used Operating Systems support this feature ?
  Need that info:</p>
  
  <ul>
  <li>Windows which versions ? </li>
  <li>Mac OS, classic Mac or Mac OS X ?</li>
  <li>Linux "Distros" ?</li>
  <li>BSD ?</li>
  <li>Other (Solaris, Unix, other)</li>
  </ul>
  
  <p>Any links ? Thanks.</p>