Live from Microsoft's Windows 10 event (pictures)

REDMOND, Wash. -- At its "Windows 10: Next Chapter" event, Microsoft demoed its Windows 10 operating system across numerous devices. The company also introduced its Surface Hub service and its augmented reality platform, Windows Holographic with HoloLens.

Inside Microsoft's Redmond campus. The company also showcased Continuum and the new Project Spartan Web browser.

Settling down into the keynote room.

Terry Myerson, Microsoft's executive VP of operating systems, takes the stage.

Myerson laying out how Windows 7, 8.1, and Windows Phone 8.1 can update to Windows 10, with free upgrades for the first year.

Joe Belfiore, Microsoft's corporate VP of its operating systems, comes onstage for a deeper dive of Windows 10 across several devices.

Windows 10 displayed on an 8-inch tablet. The device is running a full version of the OS and can be docked to a keyboard and connected to a mouse.

Cortana, Microsoft's digital assistant, lands on the PC. Here, she calls up the weekly weather forecast.

Cortana keeps a notebook of a user's interest and information in order to keep ahead on relevant information, such as favorite sport teams and stocks.

Belfiore drafts up an email via voice with Cortana.

Belfiore moves on to Windows 10 on mobile.

Here, Windows 10 and its familiar tile interface are displayed on a Lumia 1520 handset.

A quick overview of Cortana's new features on the PC.

Microsoft Office, the company's popular productivity suite, also gets a facelift. Here, Word is displayed on a smartphone.

PowerPoint on mobile, which features new animations and can support MirrorCast.

To show the continuity of the OS across devices, Belfiore calls up the email app for Windows 10 on desktop (left) and mobile.

The calendar app on desktop (left) and mobile.

Stored photos on desktop (left) and mobile.

Skype on mobile (left) and desktop.

Maps on mobile (left) and desktop.

Belfiore wraps up his app demo with (codename) Project Spartan. As predicted, it is Microsoft's entirely new Web browser for Windows 10.

Spartan integrates a real-time annotation feature that can work with touch and non-touch devices.

The new browser also has a reading mode, similar to Apple's Safari, that formats articles in a way that's easier to read. It also has a reading list, another favorite of other modern browsers.

Cortana is also baked into Spartan. For example, Cortana autofills a search for the airline Delta with Belfiore's wife's flight information pulled from his other apps.

An overview of Project Spartan, which will arrive first on desktop for Insider users, and then mobile.

Next up is head of Xbox Phil Spencer to discuss entertainment on Xbox and PC.

Spencer unveils the Xbox app for Windows 10. Sporting a similar to Steam, the app is accessible for Xbox Live subscribers.

The app lets you share videos from your Xbox, and keeps track of what's happening in your gaming circles with its Activity Feed, which is a Facebook-style recap from your friends' list.

Lauren Carter from Lionhead Studios comes onstage to demo cross-device play. Here, Carter is on an Xbox One playing Fable Legends with  Spencer, who in turn is playing on a PC.

Spencer also explains that with Windows 10, users can stream games with any device running the OS later this year. For example, if you establish a link between your Surface Pro 3 tablet and your Xbox One, you can stream  console-exclusive games like Forza Horizon 2.

Myerson returns with a quick overview of Windows 10. Microsoft will release a new build of the OS to its Insiders next week, after the Super Bowl. Windows 10 will then launch on mobile phones.

Switching gears, Hayete Gallot, senior director of security business, unveils its Surface Hub service on an 84-inch 4K display with built-in cameras, speakers, mics, Wi-Fi, Bluetooth and NFC.

The Hub is a platform that facilitates workplace meetings and collaboration, as well as display large-screen apps. For example, it can run OneNote, where people can annotate presentations in real-time with a stylus. Here, a Siemens application showcases a 3D model.

A quick overview of the new Surface Hub platform.

Microsoft's Alex Kipman comes onstage to introduce Windows Holographic.

Windows Holographic is an augmented reality (not virtual reality) platform, which is Microsoft's take on Google's now-defunct Glass project.

The Microsoft HoloLens is an untethered holographic computer with see-through high-def lenses, spatial sound, motion sensors and a built-in CPU and GPU.

The HoloLens also has a third processor: a holographic processor unit. The HPU takes in a user's view, gesture and voice to spatially map out his or her environment.

With HoloStudio, users can create holograms of themselves and objects and interact with them. Here, the user is designing a quadcopter.

Because holograms behave like real-world objects, they can be printed in real life. Here, Microsoft 3D-printed the same quadcopter seen before, which was designed entirely in HoloStudio.

CEO Satya Nadella comes onstage. "Windows 10 is the home for the very best Microsoft experiences," Nadella says. "We're going to have services everywhere. When it comes to Windows, we're not building apps, but harmonizing experiences."

Myerson closes the presentation prior to the Q&A session. He notes that Windows 10 will be on phones, tablets, PCs and Xbox, but does not disclose exact release dates. Click here to read everything you need to know about Windows 10..