Microsoft is creating a new version of Windows 10, designed exclusively for dual-screen and foldable devices. Windows 10X, also known by codename “Santorini,” is an ambitious effort from Microsoft to redesign Windows 10 for devices that don’t even exist yet — like flexible tablets that morph into being capable of laptop-like tasks — devices like the Surface Neo.

Microsoft created the original Surface tablet and laptop hybrid more than seven years ago. In the intervening years, it changed from something that was weird and poorly executed into the flagship Windows device. Now, Microsoft is ready to try something bold and new again.

“We see people using laptops. We see people using tablets. We saw an opportunity both at Microsoft and with our partners to fill in some of the gaps in those experiences and offer something new,” explains Joe Belfiore, head of Windows experiences, in an interview with The Verge.

The Surface Neo is Microsoft’s own vision of where Windows 10X will shine. It looks like a big, metal Moleskine journal when it’s closed. But inside, there are two separate 9-inch displays that fold out to a full 13-inch workspace. The Surface Neo really feels like Microsoft’s original Courier concept from 10 years ago is coming to life.

Like most Surface devices, there’s an intricate hinge that allows the Surface Neo to switch into a variety of modes and the typical high build quality you’d expect from Microsoft’s hardware. There’s also a clever Bluetooth keyboard that flips, slides, and locks into place with magnets, which can be stowed and secured to the rear of the device. There’s even a new Surface Slim Pen that attaches magnetically, and it’s the same stylus Microsoft is using on the new Surface Pro X.

You could use it as a laptop, a book, or a tablet in ways we haven’t exactly seen before. Microsoft isn’t revealing much more about the Surface Neo hardware just yet, but Intel Lakefield processors will power the device. Dell, HP, Lenovo, and Asus are all also working on dual-screen or even foldable devices that will also run Windows 10X, so this isn’t just a Microsoft and Surface effort.

Microsoft created Windows 10X in collaboration with its Surface hardware team, though. “So when we first got started on this project, obviously, we didn’t have the hardware to start with,” reveals Carmen Zlateff, engineering lead on Windows 10X, in an interview with The Verge. “So we do all of our prototyping on the Surface Go and Surface Pro... and as soon as the hardware is ready, we started to move that over. We were able to start long before the hardware was actually ready.”

This is a key partnership. We saw a variety of OEMs experiment with wacky Windows devices back in the Windows 8 days and even some dual-screen hardware previously, but none of it has really had deep support within Windows itself. So the results have always been a Frankenstein’s monster combination of software and hardware. This time, the software and hardware will be tightly integrated. For that reason, current Windows 10 devices will not be able to upgrade to Windows 10X, Microsoft says.

At first glance, the device looks like two Surface Go displays slapped together, and the gap between the displays on Microsoft’s Surface Neo is clearly visible. This is intentional so that the displays can act independently and alongside each other. Central to how this all works is Microsoft’s idea of “postures,” which is the term the company uses for the various modes Windows 10X supports. There are more than you might expect.

”We think these new dual-screen devices can help our customers bridge the gap between consumption and productivity,” says Belfiore. “These devices go beyond a conventional laptop and tablet because they support some interesting new postures.”

Microsoft envisions people using these devices in a variety of scenarios, some that are even identical to how people currently use a laptop. You can spin the device around, and apps and content will reflow intelligently. Microsoft’s Office apps even make clever use of the second display by adding things like a slide list in PowerPoint.

You’ll be able to use Windows 10X devices in a number of ways:

Note-taking: This mode lets you have one full-screen app on each display, where one could be a browser at the top showing some video content, and the other could be a note-taking app that a student is using in class. A pen can be used to take notes or even a separate hardware keyboard.

This mode lets you have one full-screen app on each display, where one could be a browser at the top showing some video content, and the other could be a note-taking app that a student is using in class. A pen can be used to take notes or even a separate hardware keyboard. Mobile presentation: This places content like a PowerPoint deck on the outside of the device, while you can read notes on the inside and control it with a keyboard.

This places content like a PowerPoint deck on the outside of the device, while you can read notes on the inside and control it with a keyboard. Portable all-in-one: This places the dual-screen device in a book mode where it can stand on a flat surface, and you use a detachable keyboard to work. It’s similar to how you might use a dual-monitor setup at home.

This places the dual-screen device in a book mode where it can stand on a flat surface, and you use a detachable keyboard to work. It’s similar to how you might use a dual-monitor setup at home. Reading: This mode involves using the device like a book with one or two hands, and the ability to use a stylus for light note-taking.

This mode involves using the device like a book with one or two hands, and the ability to use a stylus for light note-taking. Laptop: You’ll be able to use a software or hardware keyboard on one display, with the typical content on the primary display up top.

While reading, presentation, and all-in-one modes are what you’d expect from dual-screen devices, it’s the laptop mode that I was most intrigued by. “These devices can have software keyboards as well as hardware keyboards,” explains Zlateff. “We know that while people have learned well on mobile devices how to type on a screen, it’s just still hard to do that on a PC form factor.”

On Microsoft’s own Surface Neo device, you can slide a hardware keyboard into place on top of one of the displays, and it can be used in clever ways. Unlike all of Microsoft’s other Surface devices, this keyboard attachment doesn’t have a trackpad. Instead, the display acts as a trackpad below or above the keyboard, depending on where you place it. Most modern trackpads are made out of glass, so Microsoft believes it’ll feel natural to use.

What’s really different here compared to regular laptops is the ability to move the keyboard around freely. Depending on where you place it, Windows 10X might display a new rich input area above the keyboard area that Microsoft is calling WonderBar. It’s similar in concept to Apple’s Touch Bar, but it’s less restrictive and — of course — bigger.

It’s an area where you can pop in a picture-in-picture version of a YouTube video or access emoji and GIFs for when you’re replying to messages and emails. Microsoft is considering allowing people to use inking in this section and working with app partners like Netflix and Spotify to optimize apps for this area. It feels like there’s a lot more to come from the WonderBar.

Elsewhere, Windows 10X looks and feels a lot like Windows 10. “Our intent here is that fans of Windows 10 will be able to use Windows 10X with no learning curve,” explains Belfiore. “We want the navigation functionality to feel familiar. We want them to be able to get the apps they want to use. We want them to have no doubt that it’s Windows 10.”

Microsoft hasn’t totally ditched its Windows roots here. “We did not wipe the slate clean. Instead, we’re evolving the core of Windows 10,” says Belfiore. “What we’re building is an evolution of where we’ve been going with Windows 10, and it’s OneCore tech.”

OneCore is a shared set of technologies that Microsoft has been working on to allow Windows to span across device types from desktop PCs to things like the Xbox One console and HoloLens headset. Windows 10X is now part of this same family of devices.

I know what you’re thinking: what about apps? Windows 10X, like Windows Phone, could live by the apps and software that really take advantage of these dual displays, or it could die by the lack of apps available.

Microsoft is trying to tackle the problem in two ways. The first is simply encouraging Windows app developers to create apps that intentionally take advantage of the hinge. Microsoft calls this “app enlightenment.”

“We’re working to take the best of the applications that people need and use most — things like Mail, Calendar, and PowerPoint — and bring them over to dual screens in a way that creates flexible and rich experiences that are unique to this OS and devices,” explains Zlateff. “Our goal is that the vast majority of apps in the Windows Store will work with Windows 10X.”

This also means you’ll be able to load regular win32 traditional desktop apps on Windows 10X. Microsoft is using a container technology to allow legacy apps to run but not massively hit the battery. That’s important because these new dual-screen devices have to power a whole extra screen compared to traditional laptops or tablets. That means Microsoft has to be smart with battery life. Microsoft isn’t saying exactly how this container tech works, but it sounds like traditional apps will run in an isolated container rather than being fully virtualized, as there’s no need to run a virtual machine when there’s an Intel processor inside. Microsoft is promising more software information at Build in May 2020.

Outside of traditional Windows apps, Windows 10X will rely on Progressive Web Apps (PWA), Universal Windows Apps (UWP), and apps that blend local and web code to take advantage of the dual displays. Microsoft really hasn’t had much luck attracting developers on Windows 10 to build its Universal Windows Apps, and the company has expanded the definition of these modern apps so far that it now essentially means any Windows app. That flexibility might be key, though. Unlike failed initiatives like Windows RT or Windows 10 S, you’ll be able to download any app and install it just like you would on a regular Windows 10 desktop PC. That should help bridge the gap of apps until ones appear that are really optimized to take advantage of dual displays.

Microsoft is also making some changes to the UI in this version of Windows. Live Tiles are gone from the Start Menu, replaced instead with a list of apps, documents, and files. It’s a Start Menu that better reflects what you’ve actually been doing on your device, instead of lots of tiles animating the weather or news.

“We think this feels familiar to people who are using tablets and mobile devices today, and we’ve tried to use the screen real estate in a way that combines app launching with suggestions of things like websites, documents, or things you’re working on,” explains Belfiore. “We’re trying to really strike a great balance between familiarity and progress.”

Outside of apps, I think a lot of people will question the need for dual-screen devices initially. It’s difficult, without trying one of these devices, to appreciate the need for something beyond the tablet and laptop. But Microsoft is convinced they’ll be part of the future. “Think of the mom sitting at the soccer practice being able to work on her proposal or completing some work on the bus on the way home,” explains Zlateff. “For anyone who needs to have increased productivity throughout the different phases of their day, this device is for them.”

For Microsoft, this is still all super early, especially on the software side. Although we were able to touch the Surface Neo, we weren’t able to capture a full hands-on video as the software and hardware are still in development. Devices from OEMs and even Microsoft won’t go on sale until fall 2020, and the next year will be spent refining the software and hardware. Right now, Microsoft and its partners are experimenting with hardware that is between 9 and 12 inches diagonally per display.

“We don’t imagine this going to very small devices,” says Belfiore. Windows 10X isn’t designed for smartphone-like devices that fold out into tablets. This is more for tablets transforming into laptops, a strength that Microsoft has focused on for its Surface line. But that’s not to say the company isn’t thinking about smaller dual-screen devices — a smartphone-sized Surface Duo running Android is also in the works.

A lot of things could change before these devices end up in consumers’ hands. “One of the reasons we’re talking about this now is getting unique hardware built and having it available to our ISVs (independent software vendors) and having the user experience, really, this is a thing the ecosystem will evolve toward doing,” says Belfiore. “We do recognize it’s early. There’s lots that could change as we iterate and listen to people’s feedback, but we wanted to get started and let the world know we’re doing this.”

Microsoft has some serious competition, too. Google is adding native support for foldable devices into Android, and Samsung has even shipped its foldable Galaxy Fold device. LG has also created a dual-screen Android phone, and there’s bound to be more experiments in the year ahead. Microsoft is focusing on its strengths of transforming a tablet into a laptop, while Android phone makers are attempting to convert phones into tablets. As the technology matures over the next decade, we could even see phones that bend into tablets and laptops.

Microsoft has now set the stage for its dual-screen and foldable ambitions, and it’s now up to Surface and Microsoft’s OEMs to deliver the promised software and hardware experience.

As futuristic as this Surface Neo hardware looks, the truth is that its success or failure will be decided by Windows 10X. “For us, it’s an opportunity to do innovative work, to try to meet customers where they’re at, and enable people to do things they haven’t done before,” explains Belfiore. “It’s an area we’re just excited about.”