While writing tutorials on Flex & Actionscript I found the need to paste MXML code into my HTML documents. Well, if you've ever tried to embed non HTML XML tags in your document, you'll know that these tags do not show up. To make them appear, you have to convert the characters into HTML Entities.
The HTML Entities are just a way for the browser to display non-alphabetic letters like '<' and '>'. For instance, to display a '<span> tag you must replace '<' with the <.
To prevent myself from hand coding this for every occurrence in an article, I wrote a flex app. Simply paste the text you wish to have encoded in the left text area and click to "Convert to HTML Entities" button at the bottom.