Why does the default mvc6 template target multiple DNX Versions?

Question

When creating a new MVC 6 project using asp.net 5, there are reference to both DNX 451 and DNXCore50.
Why are multiple DNX Versions referenced and are they both necessary?

Answer 1

DNSCore50 uses .net core and DNX451 uses the .net framework. Referencing them both means you can build for both targets.

If you don't want to build for both you can remove one of them.

Reasons why you might want to keep both might be that you are making a library that you want to be available for external projects of both types.

Reasons why you might not want to keep both might be that you are using an external library that is only available for one of them (there's a good chance that most of your favourite libraries are framework only), or perhaps you need to use framework code that has not yet been implemented in .net core.