They changed the name to Modern UI, some reported [1] because it clashed with their German partner Metro AG. In any case Modern UI started with Zune and you could get for the time nifty looking media player for it on XP [2]. You can still see it in newer parts of Windows 10 with its aversion to skeuomorphic design, preferring text and minimalist 1 color icons.
[1](https://arstechnica.com/information-technology/2012/08/micro...) [2] https://archive.ledfrog.com/2011/06/microsoft-zune-software-...