[WindowsCentral.com]

One of the most exciting things Microsoft announced at Build 2017 was the Fluent Design System (formerly codenamed Project Neon). Not because of the name, which is a bit clumsy, but rather the theory underlying Fluent Design.
While the current look of Windows 10 carries many of the original "Metro" design principals, there has been a lack of structure for app developers. Gone was the strict mantra behind the Metro design language – the "content before chrome" that provided clear principals and goals. Instead, the design seemed ad hoc and inconsistent.

Full story from the WindowsCentral blog...