I want to make a page for a website that will let the user create a blog post, and want them to be able to graphically edit the formatting, like paragraphs and styles, then convert this to html. Is there a way to do it in PHP? Do I need to use Javascript or Ajax or something?
PHP (if you want dynamic behavior) with FCKeditor (on the client side) will do the job. Have a look at the demo. Another good editor is TinyMCE.