Microsoft's Windows Phone head marks Metro's third birthday

On Oct. 11, 2010, Microsoft officially ditched its outdated Windows Mobile operating system in favor of Windows Phone 7, and the company celebrated with a big press event to show off the first Windows Phone 7 devices (though the phones would not go on sale until Oct. 21). Today, Microsoft's Windows Phone head Joe Belfiore posted up a reminder on the Windows Phone 7 anniversary on his Twitter feed.

The Dell Venue Pro was one of the first Windows Phone 7 smartphones.

His Twitter post was also a reminder that the launch of Windows Phone 7 was the first appearance of Microsoft's Metro user interface of colorful flat tiles made for touchscreens.

Microsoft has since extended the Metro UI to its other operating systems. In 2011, the Xbox 360's dashboard was changed to make it look like the Metro interface. Windows 8 and Windows RT included the Metro look in addition to retaining the traditional desktop interace when they were released in 2012. The upcoming Xbox One will also have a Metro-inspired dashboard when it launches in November.

In mid-2012, Microsoft stopped using Metro as the brand name for the interface, which it now primarily refers to as "Modern." Microsoft has never gone on the record on as to why it ditched the brand, but a Germany company was reportedly threatening Microsoft with a trademark lawsuit if it didn't change the name. Still, the fact that Belfiore even mentioned "MetroUI" in his Twitter post shows that the brand hasn't totally been wiped from the minds at Microsoft.

Source: Joe Belfiore on Twitter | Image via HTC