April 12, 2010
.NET 4.0 and C# 4.0 released
MicrosoftThe software giant behind Windows, Office, Azure, and Xbox — founded by Bill Gates and Paul Allen. shipped .NET FrameworkMicrosoft's original managed runtime for Windows — CLR, BCL, and WinForms/ASP.NET stacks. 4.0 on April 12, 2010 with C# 4.0 dynamic typing, optional parameters, and `async` preparation via the Task Parallel Library.
What it was for
C# 4's `dynamic` keyword made COM and Office automationUsing machines or software to perform tasks with minimal human intervention. less painful; optional and named arguments cleaned up APIs. The Task Parallel Library laid groundwork for `async`/`await in C# 5 — keeping .NET competitive for Windows desktop and server through the 2010s.
Companies
- Microsoft
Why it's here
C# 4 added dynamic interop and TPL — stepping stones to modern async .NET.
Why it mattered
Dynamic typing bridged C# and scripting/COM worlds without abandoning static safety elsewhere.
What it solved
Office and legacy COM APIs were painful to call from strongly typed C#.
Media
- Image.NET Framework
Microsoft, Public domain, via Wikimedia Commons
Related
- .NET 3.5 and C# 3.0 with LINQ releasedNovember 19, 2007
- .NET Core 1.0 releasedJune 27, 2016