Google's first Chromebook was the kind of laptop you'd design if you didn't give a damn about laptop design. It was thick, heavy, rubbery, boring, and black. Black keys, black body, black trackpad, black everything. Everything about the Cr-48 was designed to communicate that this device was still an experiment. Even the name, a reference to an unstable isotope of the element Chromium, was a hint at the chaos raging inside this black box. "The hardware exists," Sundar Pichai told a crowd of reporters at the Cr-48's launch event in December of 2010, "only to test the software."

Moments later, Eric Schmidt took the stage and preached about how the "network computer" tech-heads had been predicting for decades was finally ready to change the world. "We finally have a product," Schmidt said, "which is strong enough, technical enough, scalable enough, and fast enough that you can build actually powerful products on it." Apparently already sensing the skeptical feedback Chrome OS would get, he gestured toward the audience and told them "it does, in fact, work."

For years, the knock on Chrome OS was that it was "just a browser." A PC, people thought, had to be more than that. But now, almost six years since that first Chromebook, just a browser has turned out to be just enough for a growing group of users. Chromebooks outsold Macs for the first time in the first quarter of this year, and according to Google, US schools buy more Chromebooks than all other devices combined.

The CR-48, Google's first Chromebook. Google

Even now, the Chrome OS revolution is only beginning. In the next few weeks, Chromebooks will suddenly have access to the millions of apps in Google's Play Store, which will work on a Chrome OS device the way they work on Android phones. Also, Google's beginning a big move into the boardroom, trying to convince businesses to use Chromebooks instead of their old Windows XP machines. And a whole new breed of Chromebooks is about to hit shelves. Not only are they high-end, they're going to be completely different from the laptops we've known before.

Getting Online

Way back in 2006, Kan Liu started at Google working on Windows apps. Yep, Google used to make useful and popular Windows apps: a toolbar plugin for Internet Explorer, and a Desktop Search app that indexed your computer to make stuff easier to find. Even Liu thought the projects were weird. "If you thought about what Google was," he tells me, "you'd be like wait, they make a download manager for native apps that you can download on Windows machine?"

These apps were supposed to be fast, simple, and secure. But because Google couldn't control Windows, it really couldn't guarantee any of that. Boot times really drove them crazy. "Computers used to take, like, minutes to boot up," says Caesar Sengupta, one of the original leaders of the Chromebook project. Tired of this unacceptable offense, a few people on the team started hacking around on an old netbook in the office, taking out whatever didn't make sense—like the fact that Windows still checked for a floppy disk every time it turned on. Without even trying that hard, the team hacked together a Linux-based setup that went from off to online in ten seconds flat. Suddenly Google was in the OS business.

The projects that last within Google—the ones that aren't Reader or Buzz or Wave or Currents—are the ones that scale. "If you want to do something at Google," says Felix Lin, the VP in charge of all things Chromebook, "it really only makes sense to do it at Google if what you're building can touch everybody in the world." Lin came to Google with a singular mission: to build the company's browser into an operating system that would make computing and computers accessible to more people. That meant making computers cheap enough so more people could buy them. More important, it meant removing settings, options, icons, buttons, and toolbars in an effort to make computers easy enough that anyone could use them. Particularly the billions of people who hadn't used a computer before.

When the first Chromebooks launched in 2010, anyone who'd ever used a PC decided something felt a little bit...off. "Among the many things you can't do," Laptop Magazine wrote, "is view the system properties to see exactly what hardware the computer has, so if you need to know how much free space is left on the system's internal storage or what type of CPU you have, you're out of luck. Nor can you control the power settings." Notebook Review concluded its assessment with the phrase that still haunts Chrome OS: "So...it's just a web browser?"

Thinking about those early reviews makes Sengupta laugh. "The first people who bought Chromebooks were people who were computer folks," he says. "They looked at the Chromebook and said, 'This is not a real computer, it doesn't have very many settings!'" They hated that you couldn't find your files, or change the time setting. But why in the world, Sengupta argues, would any rational person want to manually change the time on their computer? It should just know. "The amount of work it took to eliminate all the settings," he says, "so that you didn't have to care and feed for your computer, was the thing that really made it successful."

The Chromebook Pixel, one of the Google-made Chrome OS devices. Josh Valcarcel/WIRED

One place a super-simple, fiddle-free OS took off: schools. They loved that Chromebooks were cheap, easy to administer, and great for multi-user environments. Then it was businesses, which, well, same thing. Next, Chrome OS is out to convert everyone else. The Chrome OS team was a little early to the idea that people could do their work and live their lives inside a tab or six, but history has proven them right.

That's not to say the Chrome OS crew are fortune-tellers, of course. They did miss out on one very important thing: smartphones. You may have heard of them. "Back when we were starting Chrome OS," Lin says, "the web and mobile were in a dead heat. We were betting big on the web, and the Android team was betting big on mobile." He doesn't say the obvious next part, which is that mobile and Android won.

The Chrome OS team was right about a long of things, but it never saw mobile coming.

There are still times when you want a keyboard and trackpad, though, or a screen larger than the palm of your hand. And lucky for the Chrome team, Android's also part of Google. So the two teams started talking about how to integrate. They had lots of concerns about performance, integration, and above all security. A couple of years ago, a Chrome engineer ran an experiment: He took containers, a way of separating parts of a system that's common in data centers, and ran them on a local machine. Android in one, Chrome OS is another. "A few of us saw it," Sengupta says, "and our eyes literally opened up." That was the answer.

Android apps solve a couple of Chrome OS's lingering problems. Most important, they bring all the software people are now accustomed to using, onto a new platform. Remember when people used to complain about Chromebooks not having Word? There are now billions of people who now reasonably expect their laptop to have Snapchat and Uber. Apps also offer offline support in a much more robust way, and they bring the kind of multi-window, desktop-app functionality that feels familiar to the old-school Windows users. Of course, they also require totally different things than traditional computer software. Most apps assume you're using them on small, touch-enabled screens, running on devices with cellular connections and a bunch of sensors that you definitely don't have in your laptop.

So, OK, new question: what does a laptop look like in the age of mobile?

New Puzzle Pieces

Imagine you want to build a Chromebook. Great idea! Before you can do anything, you have to deal with Alberto Martin Perez, a product manager on the Chrome OS team. Perez is the keeper of Google's documentation, the huge set of requirements and standards given to all Chromebook makers. The documentation is an ever-changing organism, concerned with everything from how much RAM and battery life a Chromebook needs, to how hard you have to press the trackpad before it registers as a click. If your Chromebook takes more than ten seconds to boot, or the power button isn't on the top right? Get on the plane back to China and try again. The long, complex document is written in engineer-speak and is remarkably detailed. It's Google's first line of defense against corner-cutting manufacturers.

When Google decided to integrate Android apps with Chrome OS, Perez and his team combed through the documentation. "We wanted to make sure we were ahead," Perez says. "It's really easy to change a web app, it's really hard to change a laptop." Google now strongly recommends—which is a lightly-veiled warning that it'll be mandatory soon—that every Chromebook include GPS, NFC, compass, accelerometer, a fingerprint reader, and a barometer. Those are all smartphone parts that have made little sense in a laptop before. But Android apps are inspiring manufacturers to make devices that move, that adapt, that take on different forms in different contexts.

The Acer Chromebook R13 is one the the first convertible Chromebooks. It won't be the last. Google

Computer industry execs believe Chrome OS has come into its own, that people will now choose it over Windows for reasons other than price. For many new customers, says Stacy Wolff, HP's global head of design, "their first device was a smartphone. And they look for the cleanliness, the simplicity, the stability of what we see in those devices." That's the thinking behind the sharp and business-like HP Chromebook 13, the company's new $500 laptop. Wolf sounds eager to continue down the fancy road, too: When I ask why the Chromebook 13's not as nice as the Windows-powered Spectre 13, which is one of the best-looking and lightest laptops ever made, he pauses to make sure he's not giving too much away. "I can't talk about the future, but there's nothing that stops us from continuing to go and revolutionize that space." The $1,000 Chromebook used to be a silly sideshow, Google's way of overshooting. Soon enough, it'll be a totally viable purchase.

The next few months are shaping up to be the PC market's most experimental phase in a long time. The addition of Android apps "begs for higher performance hardware and new form factors to support these new use cases," says Gary Ridling, Samsung's senior vice president of product marketing. Batteries are more important than ever, as are touch-friendly displays. Windows manufacturers have been experimenting with convertible and detachable devices for the last few years, but the combination of Android and Chrome will actually make them work.

The results are already starting to trickle out. Acer announced the Chromebook R13, which has a 1080p, 13-inch touchscreen that flips 360 degrees, along with 12 hours of battery, 4 gigs of RAM, and up to 64 gigs of storage. It'll only get crazier from here: you'll see laptops that are maybe more like tablets, a few that are maybe even a little bit like smartphones, and every imaginable combination of keyboard, trackpad, and touchscreen. Google and its partners all see this as the moment Chromebook goes from niche—for school, or travel, or your Luddite dad—to mainstream. "The ability to run their favorite apps from phones and tablets," Ridling says, "without compromising speed, simplicity, or security, will dramatically expand value of Chromebooks to consumers."

When the legendary Walt Mossberg started his personal technology column at the Wall Street Journal in 1991, he opened with a now-classic line: "Personal computers are just too hard to use, and it isn't your fault." 25 long years later, that story's finally changing. Chromebooks are exactly the computer the world needs now: simple, secure, usable. They just work. And starting this fall, they'll work the way people do in 2016: online everywhere, all the time, in a thousand different ways. "Personal computing" left desks and monitors behind a long time ago, and personal computers are finally catching up.