Special thanks to the Big Box PC Game Collectors community for turning me from a video game-loving private citizen into a cardboard-crazed computer addict. It is the dark side, where productivity software is literally the devil, and stacking is a crime punishable by death...or worse.
In all seriousness, it's a great place where you can go to chat with John Romero.
Shout-out to MobyGames and GUIdebook Gallery, two of the best resources on the Web - as long as you need what they have, of course. MobyGames' ever-growing database of video games is a wonderful font of knowledge for us lowly enthusiasts, and GUIdebook is a collection of very useful screenshots from different operating systems over the years.
A few photos, such as this one, this one and also this one, are used by permission of their respective creators. Thanks to the Unsplash community for providing free high-quality photos such as these for everyone to use.