Microsoft .NET is an open-source development platform for building both simple and robust applications. It has an extensive library created by Microsoft with multiple platforms including .NET Core and Xamarin/Mono (For mobile applications). When you combine .Net and Microsoft's Cloud ecosystem, Azure, you end up with a powerful platform to deploy scalable systems to. Below are some of the many features that make .NET such a powerful tool for developing robust software applications. When you combine .Net and Microsoft's Cloud ecosystem, Azure, you end up with a powerful platform to deploy scalable systems to.