It's hard to grasp the breathtaking scale of the epic war between Microsoft, Google and Apple. Billions upon billions of dollars. Entire industries at stake. This is the board. These are the pieces.

If you think about it, what's shocking isn't the size of Microsoft or Apple, companies that are decades old, established titans of industry (even if they have stumbled in the past) – it's Google. In just over 10 years, Google's become arguably the most important company on the web, spreading to anything the internet touches with astonishing speed, almost like a virus: From the web and search to books, video, mobile phones, operating systems, and soon, your TV.

Friends have become enemies, enemies more paranoid. And you know, it's only a matter of time before Google's remaining gaps on this map are filled out. (BTW, you can click on the picture to make it bigger.)

Back in the 1990s, "hegemony" was another way to spell "Microsoft." It was Microsoft that looked to invade everything. It was Microsoft in the Department of Justice's sights for antitrust issues. Anywhere there was computing, there was Microsoft. But today, it's Apple that conquered music. Apple that revolutionized mobile phones. Apple that might make tablet computing mainstream. Not Microsoft. As the incumbent, Microsoft's not going anywhere. But it plays catch up more often than it leads, at least when it comes to the things people care about now, like the web and mobile.

What's at stake? Nothing less than the future. Microsoft wants computing to continue to be tied to the desktop – three screens and a cloud, as Ballmer is fond of saying. For Apple, it's all about closed information appliances with lots of third-party apps, computers anybody can use. And for Google, all roads lead to the internet, and the internet is synonymous with Google.

This isn't a road map. It's a study guide.

Image created for Gizmodo by Shane Snow

Updated graphic, changing Android Marketplace to Market

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