.NET 11 and C# 15

11th November 2026 · by David Gardiner

.NET 11 is out, with a heap of new features, including C# 15

This week is .NET Conf at which the general availability of .NET 11 will be announced.

.NET 11 includes updates to the runtime, libraries, SDK, ASP.NET Core, EF Core, Extension libraries, Windows Forms, WPF, F# 11 and C# 15.

Speaking of C#, here’s the full list of new language features in C# 15:

• Collection expression arguments
• Union types
• Closed hierarchies
• Extension indexers
• Labelled break and continue
• Non-virtual static interface members for older runtimes
• Memory safety (preview)

Over the next few days I’m going to be digging into what I think are the more interesting ones. I’ll see you shortly!