How does WPMUDev display their themes and plugin pages?

I'm in the process of building a membership site for a customer. They're using LearnDash to build the courses. In addition to the courses, there are lots of other available resources that members will have access to download.

I like the way this is done on the wpmudev site. It appears that each plugin or theme you have has it's own post page. I noticed that when I visit a plugin page, I see the word "project" in the URL. For example:

Can you tell me if you're using another plugin in conjunction with posts to display your themes and plugins? I've used themes in the past that create their own "project" type of post, but I wasn't sure if your setup is part of the theme you use, a plugin, or both?

Like I mentioned, I really like the way it's set up on your site so any info you can provide in how it was done would be great. Thanks!!