I use the WordPress plugin "SyntaxHighlighter Evolved" to show code snippets. You can see a live example of mine here: http://otscripts.com/sunshop-modifications-part-6/
- the way I do this in the WordPress editor is by switching to the Text tab (rather than the Visual tab), type the [ php ] or other shortcode, paste in the preformatted text, and finish with the [ /php ] shortcode.
So far I have not figured out a way to do this with MarsEdit. Suggestions? Thanks!