.NET 9 preview: new features and updates

A new era of cloud-native application development and performance optimization is ushered in with .NET 9, the successor to .NET 8. It will be supported for 18 months as a Standard Term Support (STS) release. Here’s what you need to know about it:

1. .NET Runtime:
   • Several performance enhancements are included in the .NET 9 runtime, including:
     • Exception handling is faster.
     • Inline improvements for native AOT (Ahead of Time Compilation).
     • Improvements to looping and profile-guided optimization (PGO).
     • For more details, check out What’s new in the .NET 9 runtime.
2. .NET Libraries:
   • The .NET 9 Libraries have improved in several areas, including the following:
     • Serialization.
     • Cryptography.
     • LINQ.
     • Reflection emit.
     • New TimeSpan.From* overloads
     • ActivatorUtilities.CreateInstance constructor
     • And more! Explore further in What’s new in the .NET 9 libraries.
3. .NET SDK:
   • The .NET 9 SDK introduces improvements such as:
     • Enhancements to the terminal logger.
     • Tool roll-forward capabilities.
     • Enhanced unit testing support.
     • Dive deeper into the details with What’s new in the SDK for .NET 9.
4. .NET Aspire:
   • NET Aspire is a self-contained, cloud-ready stack for building observable, production-ready, distributed applications.
   • It’s delivered through a collection of NuGet packages that address the specific concerns of the cloud-native developer.
   • Currently available in preview for .NET 9. Learn more about .NET Aspire (Preview).
5. ASP.NET Core 9.0:
   • ASP.NET Core continues to evolve with improvements.
   • Blazor
   • SignalR
   • Minimal APIs
   • Authentication and authorization
   • Dictionary debugging improvements
   • Discover them in What’s new in ASP.NET Core 9.0.
6. .NET MAUI:
   • .NET MAUI (Multi-platform App UI) also receives updates. Explore them in What’s new in .NET MAUI for .NET 9.
7. Entity Framework Core 9:
   • EF Core gets better with enhancements.
   • LINQ and SQL translation
   • ExecuteUpdate and ExecuteDelete
   • Migrations
   • Model building
   • SQL Server HierarchyId
   • Tooling
   • Learn about them in What’s New in EF Core 9.
8. C# 13:
   • C# 13 ships with the .NET 9 SDK.
   • New escape sequence
   • Method group natural type
   • Implicit index access
   • Discover the latest features in What’s new in C# 13.

Remember, with a focus on productivity enhancements, streamlined deployments, and accelerated AI integration, .NET 9 elevates cloud-native and intelligent application development. For developers across a wide range of applications, it’s an exciting release!