I would like to know if I can set up a Q&A Forum like this on my wordpress website and offer all visitors to be part of a discussion without having them to create an account or log in. I guess this is possible (as I am able to post here as well) but would like to have a confirmation and also if this is a premium feature only.

Thanks!

Hi - yes can have have guest visitors reply to a topic in a forum if you like. 

You can download a free copy of the core plugin from wordpress.org to see how it'll function.  

The premium version have a feature that marks a reply as "answered question" which would be useful in a Q&A forum.

Thanks.