C# core library for .Net Core.
This library contains "core" classes and interfaces, primarily, for UWP apps (C#). It was originally created as part of the shared libraries for the UWP apps I was building for Windows 10, and I am now in the process of open-sourcing some of them in the hope that they might be useful for other UWP app developers.
Nuget package available on Nuget Gallery:
Install-Package DotCore.Core
Note: This is for C# only, and it is not a cross-language Universal Windows Component library.