I helped someone set up discourse[1] a long time ago, don't know how it stands up these days; it's got basically zero presence in the parts of the web I'm around.
Here it says 7 comments. But you only get to see one. You have to click into the discourse post to get more. This is due to Discourse's threading model. 6 of the comments were replying to the one on the blog post itself.
What parts of the web are that, if I may ask?
I think Discourse is popular in software and tech related organizations — I see it a lot on such websites.