I've reviewed a couple options for jquery-based RTE that required PHP. I'm running a MVC/jQuery site on IIS - should i rule out php-based editors just so i can avoid installing PHP? How exactly is the client-side jquery interacting with PHP?
The reason your question is being down voted is that semantically it doesn't make any sense. It's very likely that you're not running an MVC/jQuery site as those really don't exist.
jQuery is a client-side JavaScript toolkit. This means that it is essentially a library of JavaScipt methods that you can interact with. To be a pure MVC jQuery site would entail you literally having a bunch of .htm files and your jQuery JavaScript files and serving the .htm files with JavaScript and programmatically change sections, content, all on the client-side with jQUery. This is certainly possible, but not usually done.
PHP is a server-side scripting languages that allows you programmatically decide what content to send from the server to the client. Now, many decide to use PHP to output HTML, and JavaScript that references jQuery and many do this in an MVC fashion. This may be what you're describing you have.
Now if this is what you do have, it's very important to note that the IDE you use has absolutely nothing to do with this. An IDE is a glorified text-editor. Certain IDEs will install PHP on your client machine for you solely for the purpose of local development and debugging. If the IDE/editor has jQuery support all that means is that it can aid you and catch errors while writing jQuery code.
If you're referring to a RichTextEditor, you can try CKEditor. It works pretty well with various JavaScript toolkits, like jQuery. However, there are numerous other RichTextEditors. A google search for RichTextEditor or jQuery RichTextEditor should clear that up for you.
You should try CKeditor which is a javascript based HTML WYSIWIG editor. For CKeditor it doesn't matter if you use PHP or ASP.NET on IIS.
As long as YOU KNOW how to get everything working ;)