I came to WordPress after using TextPattern for a while, and when I switched, I didn’t want to give up Textile formatting, so I found a plugin and kept using it.
That was six years ago. These days I do a lot more code samples, and trying to get characters escaped properly is becoming more and more difficult. Also, a lot of commenters have overlooked the little “Textile formatting is in effect!” message in the comment form, and their stuff has gotten screwed up six ways from Sunday.
So, with regret, I’ve just converted all the posts and comments back to regular HTML. I expect to find broken things for a while. If you notice something that doesn’t look right, please leave a comment, and I will fetch an older revision out of the database.