For lots more Windows 10 coverage, be sure to read GameSpot sister sites CNET and Zdnet. You can also see a gallery of images at the bottom of this post.

Just as expected, Microsoft on Tuesday announced a brand-new Windows operating system. During a special event today in San Francisco, Microsoft officially announced Windows 10. One major change is that Windows 10, launching to the public in 2015, effectively does away with the "Metro" tile interface from Windows 8.

But why skip over Windows 9? "Microsoft went instead with Windows 10 because they wanted to signify that the coming Windows release would be the last 'major' Windows update," Mary J. Foley of GameSpot sister site Zdnet writes.

"Going forward, Microsoft is planning to make regular, smaller updates to the Windows 10 codebase, rather than pushing out new major updates years apart," Foley added. "Windows 10 will have a common codebase across multiple screen sizes, with the UI tailored to work on those devices."

According to Zdnet's report, Microsoft will release a preview build of Windows Ten in the coming week. It is unclear when the new OS will be launched publicly, or if there is any truth to the report that Windows 8 users will get a free upgrade to Windows 10.

Another GameSpot sister site, CNET, also attended the event today, and grabbed a quote from Microsoft executive Terry Myerson about Windows 10.

"Windows 10 will run on the broadest amount of devices," he said. "A tailored experience for each device. There will be one way to write a universal application, one store, one way for apps to be discovered purchased and updated across all of these devices."

Microsoft's Windows executive Joe Belfiore added, "We want all these Windows 7 users to have the sentiment that yesterday they were driving a first-generation Prius, and now with Windows 10 it's like we got them a Tesla."

Windows 8, released in October 2012, was controversial in that it introduced a touch-focused tile design that was dramatically different to Windows 7. Microsoft addressed these criticisms with frequent--and substantial updates--including Windows 8.1. The company isn't starting over with Windows 10, but Microsoft appears to be taking a more measured approach with Windows 10.

"We believe that, together with the feedback you provide us, we can build a product that all of our customers will love," Myerson said. "It will be our most open collaborate OS projects ever."

Before today, Windows 10 was in development under the codename Threshold, which is a Halo reference.

Eddie Makuch is a news editor at GameSpot, and you can follow him on Twitter @EddieMakuch