Windows Runtime Component and WinRT Component Libraries are concepts related to language runtime interoperability in Windows Runtime - the modern development platform for Windows and typically used in Windows Store applications. Use this tag to denote any questions related to creating WinRT Components, WinRT Component Libraries and typically to limitations imposed by the rules of creating WinRT Components.
From Wikipedia:
Classes that are compiled to target the WinRT are called WinRT components. They are classes that can be written in any supported language and for any supported platform. The key is the metadata. This metadata makes it possible to interface with the component from any other WinRT language. The runtime requires WinRT components that are built with .NET Framework to use the defined interface types or .NET type interfaces, which automatically map to the first named. Inheritance is as yet not supported in managed WinRT components, except for XAML classes.
Windows Runtime applications can be written using any combinations of the three major runtimes - native, .NET and JS as long as these components are exposed across ABI (application binary interface) following rules such as - public classes need to be sealed, method arguments and return types need to be WinRT types themselves or have direct projection to those (such as Windows.Foundation.Uri with System.Uri or Platform::String and System.String or many of the other basic types having counterparts in different language runtimes).
