HTML
(real quick examples)
<P> WILL display as a single line <p>Hello world, I am Jon Doe.</p>
USE <PRE> <CODE> To retain line breaks and WHITE SPACES <pre><code>var person = [ "name" : "Jon Doe", "email" : "jon@doe.com" ];</code></pre>
THIS WILL NOT DISPLAY PROPERLY <pre><code> if (X < 10 && Y > 10) { ... } </code></pre>
USE THE CONVERTED CODE <pre><code> if (X < 10 && Y > 10) { ... } </code></pre>
PLENTY OF FREE "CODE HIGHLIGHTER" LIBRARIES ALL OVER THE INTERNET.