Try the Telerik Editor here.

    I had a great talk with the CEO's of telerik.  They informed me that their trials just show an ad every 30 requests and are the same assemblies as the up to date Telerik releases.  Ive started my first implementation of Telerik inside of rainbow.  I have easily added the Telerik RadEditor as an editor for Rainbow.  This means that any module that uses an editor can use the Telerik Rad Editor instead.  I am creating this version on our SVN.  The cool thing is that if you want to purchase a dev copy of telerik, all you have to do is replace the dlls in the rainbow /bin folder and voila.  You will have a full fledged ( without the ads) Telerik Version on your portal/application.  RadSpell comes auto inside the editor which allows easy to use Ajax spell checking.  It also inclused an XHTML checker for checking your Text/HTML for XHTML compliance.  Not too shabby.

 Below are a couple screen shots:

 

 

Update :  This shot shows the Web2.0 skin being used and improved use with apply changes only.