Displaying HTML code on pages

[eatons]

I want to be able to display code such as:

Code:

<?php
/* Credit to ccagle8 for the original function; edited by Angryboy */
function get_author_username($blogusername) { ... }
?>

In this form for tutorials about GetSimple. But even when I encode the < and > entities, they are still executed, making the code unable to be viewed and breaking the web page. This even goes for showing other bracketed codes:

Code:

(% stuff in here %)

I've had to insert spaces between the < and > signs, but I've seen other sites display their code just fine. Is there something I'm doing wrong, or could this be a server problem?

Thanks to whoever provides a solution!

Have you tried pasting your code straight into the WYSIWYG editor?
Works for me!
http://eatons.net/tutorials/innnovationoutline/