Recommend an editor

[eluser]phpserver[/eluser]
Hi,i am building a website that will be publishing tutorials and in those tutorials,there will be plenty of python,asp,php,sql etc code(i think you get the picture).Is there an editor that i can use that will allow me display the highlighting for my various code types.i.e

Code:

<?
echo 'this is the higlighting i am talking about.Notice the code is highlighted.';
?>

I like how gedit does the highlighting part,i would love to have such a system online.All ideas are welcome.

Cheers.