This codes makes the selection state (when a user tries to copy something of your code) invisible. Actually the selection is still possible but will highly confuse the user when trying to copy things from your page. This does definately not work for Internet Explorer, since it is a Webkit/Mozilla implementation. Once Internet Explorer supports basic CSS3 rules it will work there to. Up to now this code only works for Webkit (Chrome, Safari, etc.) and Firefox. In case your want to change the selection color just change the word transparent in the code with a corresponding color value (e.g. #FF0000 for red).