Windows 10's upcoming UI, previously known by its code name "Project NEON", now has an official name. At yesterday's Build 2017 event, Microsoft introduced it officially and also released an updated SDK for Universal App developers which supports new APIs. The new user experience APIs are called "Microsoft Fluent Design System".
Key aspects of the Microsoft Fluent Design System are as follows.
Material: A graphical solution which emulates the "sensory and invigorating" feel of the materials that things around us are made of.
Motion: A set of animations which give an idea on how to interact with new UI elements like an app menu opening or drawing the user's attention to controls and flyouts which appear on the screen.
Light: Soft highlights of important buttons and features to draw the user's attention.
Depth: Transition animations which make an impression of opening the next level or layer of data presented by the app.
To understand ideas behind the Microsoft Fluent Design System, watch the following video:
The company launched a new web site, http://fluent.microsoft.com/, which you can visit for more resources. If you are an app developer, you might want to get the updated SDK from the developer section on Windows Insider Downloads.