<P> Metro (officially known as Microsoft design language or MDL) is a design language created by Microsoft . This design language is focused on typography and simplified icons, absence of clutter, increased content to ratio ("content before chrome"), and basic geometric shapes . Early examples of Metro principles can be found in Encarta 95 and MSN 2.0 . The design language evolved in Windows Media Center and Zune and was formally introduced as "Metro" during the unveiling of Windows Phone 7 . It has since been incorporated into several of the company's other products, including the Xbox 360 system software, Xbox One, Windows 8, Windows Phone, and Outlook.com . Before the "Microsoft design language" title became official, Microsoft representative Qi Lu referred to it as the modern UI design language in his MIXX conference keynote speech . According to Microsoft, "Metro" has always been a codename and was never meant as a final product, but news websites attribute this change to trademark issues . </P> <P> Microsoft Design Language 2 (MDL2) was developed alongside Windows 10 . Later, the Fluent Design language extended it . </P>

Which version of windows introduced the metro user interface