Um, I don't think it's that easy.
I seem to recall that a.net's photo database is SQL
-based and runs on multiple servers. The forums look a lot like some of the PHP (that's a scripting language) systems I've seen around. Generally they use HTML templates, but I think the vast majority of the site content is dynamically generated.
Put simply, that means there is no web editor that's going to build you a site like a.net--you'd need to learn about database design and management, and--at the very least--need to learn how to install, configure, and run the scripts that make up the forums. To do that, it generally helps to know a little about web server administration and what to do when something doesn't work quite as expected (which is most of the time).