Tutorial on how to set up a forum like on site

I am trying to duplicate the set up of the forum on this website.

https://premium.wpmudev.org/forums/

Can you tell me if this is a stand alone forum, what plugins you are using, and if there has been extensive customization.

I really like ever way thing is set up and am having a horrible time using bbpress / buddypress to make a forum look like this,

Is there a tutorial on how this is set up.