Adjust the code in our tour and/or our GeoDataWriter so that text like this

<![CDATA[

<h1>CDATA Tags are useful!</h1>

<p><font color="red">Text is <i>more readable</i> and

<b>easier to write</b> when you can avoid using entity

references.</font></p>

]]>

as described inside

https://developers.google.com/kml/documentation/kml_tut#descriptive_html

It should be possible to write the text inside the description field of the "Add Placemark" dialog. And the balloon should look as specified. Saving and Loading the KML file should preserve the entered text as expected.