The following example displays the Dojo imRichEditor Widget using TinyMCE's Simple Mode. The default theme option for the imRichEditor widget is 'advanced', so you have to set the option to 'simple'. Unlike the simple example, removed the skin_variant option, so that the default silver theme will be displayed in TinyMCE's editor. I also set the toolbar_location option to top. I created this option because I personally prefer the toolbar on the top.
dojo.addOnLoad(function() {
var txt = 'Default Silver Theme';
var ta = new im.imRichEditor({theme: 'simple', toolbar_location: 'top', editorNode: "tAreas", value: txt}, 'tEditor');
});
View the source for this page to view how I setup up the widget. For documentation about the Dojo imRichEditor Widget, view my blog post.