How reliable is using contenteditable on a div for a WYSIWYG editor?

Question

I believe the title is pretty self-explanatory but still, maybe, I should ask in detail. I'm building a WYSIWYG editor and I'm really at the beginning of it. So, I realized that maybe knowing the pros and cons would enlighten me. Basically, my question is, since I want an editor that would work at least with 90% in all major browsers, how further I can go using contenteditable within a div and what are the cons and pros of using contenteditable when compared with designMode and iframe? Also, while researching I've found this editor. I believe it is not using any of these attributes and it's moving the location of textarea. Is this a better approach? Well, I know that there are lots of factors that influence the answer on the last question, but as I mentioned, the most important thing I look up in the editor is that it can be used by the 90% of the users. NB: I do not want to use any third party libraries.

Answer 1

contentEditable does not work with floats in IE:

<p>
  <img style="float:left" src="foo">
  <p contentEditable="true">very long text here ...
    ... this text won't flow round the image</p>
</p>

This is because contentEditable triggers the infamous hasLayout. Other than that, everything works pretty well.