Visual Editor
Editing text what you see is what you get with the XMLNuke.
<editform title="Visual Editor" action="module:somemodule">
<memo name="sample" caption="Memo Field" visualedit="true"></memo>
<buttons>
<button caption="View XML code selection"
onclick="alert(tinyMCE.activeEditor.selection.getContent());" />
</buttons>
</editform>
See XML of this page.
