This is what I like about the makerspace community. We get a lot of new members who almost reflectively react to the perceived "WTF are they talking about, why won't they shut up?" vibe that most people give off. It's an amazing trainwreck when they realise that they are not only not annoying people with it, but that people have an active interest!

m-ATX is if you need a computer without excessive IO, mini-ITX is when you have to choose between proper VRM and a second DIMM slot. Oh, and pay double for less than half the real estate.