The .NET Framework 4.0, released in 2010 alongside Visual Studio 2010, marked a pivotal evolution in Microsoft’s development platform. It introduced fundamental changes to the Common Language Runtime (CLR) and a suite of powerful new libraries that streamlined complex programming tasks.
First Look - WCF and WF Services in .NET Framework 4.0 and “Dublin” net. framework 4.0
In C# 4.0, the dynamic keyword allowed runtime binding, as shown in the simplified code below: The .NET Framework 4.0