Yes...

To see if that's installed:

  • Create a document, with Notepad or so.
  • Place the following lines in it:
    Code
    <? phpinfo(); ?>
  • Name it phpinfo.php (or anything, as long as it ends in .php).
  • Upload it to your server and open it in your browser.
  • Scroll down to a section titled "Apache". It will tell you which modules are loaded; if mod_gzip is listed there then it has been installed already.