NUPKG - NuGet Package is a wonderful file that is used by a software app. It is actually an extension for Microsoft Visual Studio. It includes and gives a basic interface that will handle any libraries that are third party. This wonderful extension can also be used for developing program components. You will also be able to add this program in Visual Studio’s Extension Manager if you already have it downloaded. It will definitely benefit you if you really want it. You will also be able to download this wonderful program online. It will only work if you are already using Microsoft Visual Studio.