I remember it used to be possible to see a list of everyone who had posted in a topic, with the number of posts made. I can Google up examples of this in action on older 3.4 installs like this. However, I can't reuse that url format on my (almost!) bang-up-to-date 4.3 install. 

Can I still do this? I know it's a trivial MySQL query in the database, but is it still possible on the front end? 

It's not a core feature, but there's at least one app available in the marketplace to accomplish this.

Thanks.