[elcct]

> You can mix and match elements written using different libraries, and migrate single elements from one library to another without breaking clients.

Why someone would be doing that? I mean mix and matching libraries could be asking for unmaintainable code...

[nilliams]

Because the alternative is a complete rewrite, which is usually very costly.

[spankalee]

Sure, without Web Components is might be, but Web Components and the DOM are the interop layer. As long as your component has properties, attributes, children and events, it's an element and can work with other elements. How it's implemented internally, and what library it uses, shouldn't matter at all.