We're building a custom CMS for our main site and in our admin side of it, want to be able to write news stories and have them automatically create a thread in our forum with the text for discussion. We need to write the posts in our CMS side of things because additional properties for the article, to deal with positioning and formatting need to be set. Creating a new thread from our custom PHP is no problem, I have that working. But we need a WYSIWYG editor for BBCode for our authors. The problem with using another RTE is that while syntax for the basic text formatting is pretty much standard, everyone seems to use a different format for video embeds.
I figured if we could use the XenForo RTE, it would spit out XenForo compliant BBCode I can use to create a new thread from our code, and use the XenForo parser for converting it to HTML to display on our front page, which I also have working. The RTE is the last piece of the puzzle.
It might sound like we're over-engineering this, but there's a method to our madness.