Rich text editors are hard. When you drill down into how they actually work, it's a wonder why there are so many of them, and why developers would willingly spend a significant part of their life working on one. At XenForo we have been through ... counts on fingers ... three different rich text editors in our history, so if we're being generous we can at least attest to what a feat of engineering they are and how difficult they can be to get right -- and all we have to do is implement them.
That's no easy feat either, though. We have an increasing number of features that we need from an editor, we have a layer of conversion from HTML to BB code (and back again), and we have an overall user base of millions of members across all of our...