Mostly threaded, unless I've read hardly anything in a thread. It's a bit of a pain having to jump around for the Next and Previous links, between threads though - as a Gnus user, I supposed I'm a bit spoilt when it gets to the UI department. It would be a lot better if the BBS software threw some in suitable LINKs for Next, Previous, Up and Top, so they appear in the browser's links menu or navigation bar.