In IE you can use conditional comments, these AREN'T part of W3C standards however they do not break validation.
To include jQuery.js in IE browsers ABOVE IE6 then use: <!--[if gt IE 6]> <script type="text/javascript" src="/path/to/jquery.js"></script> <![endif]--> To include in IE browsers above IE6 AND all other browsers such as firefox, safari, etc then use: <!--[if gt IE 6]> <script type="text/javascript" src="/path/to/jquery.js"></script> <![endif]--> <!--[if !IE]><!--><script type="text/javascript" src="/path/to/ jquery.js"></script><!--<![endif]-->
