.NET 4.5 brings many benefits, such as improvements in performance, compatibility, garbage collection, and new features in its structure to provide the overall scenarios it is targeted for, for example, Windows Store apps development.
One of its most important characteristics is that it is an in-place substitution of the .NET 4.0 and only runs on Windows Vista SP2 or later systems.
.NET 4.5 breathes asynchronous features and makes writing async code even easier. It also provides us with the Task Parallel Library (TPL) Dataflow Library to help us create parallel and concurrent applications.
Another very important addition is the portable libraries, which allow us to create managed assemblies that we can refer through different target applications and platforms, such as Windows 8, Windows Phone, Silverlight, and Xbox.
We couldn't avoid mentioning Managed Extensibility Framework (MEF), which now has support for generic types, a convention-based programming model, and multiple scopes...