.NET 9 introduces a variety of features and enhancements aimed at improving performance, simplifying development, and expanding the capabilities of the framework. Here are the key features of .NET 9:

Key Features of .NET 9

Performance Enhancements

  • Dynamic Garbage Collection: The runtime now includes dynamic adaptation to application size, optimizing memory usage and performance based on the application’s needs.
  • Improved Runtime Optimizations: Enhancements such as loop optimizations, inlining, and Arm64 vectorization contribute to faster execution times and reduced memory consumption.

New SDK Features

  • Workload Sets: The SDK introduces workload sets that maintain all workloads at a specific version until explicitly updated, improving version management.
  • Parallel Unit Testing: Improved integration with MSBuild allows for parallel execution of unit tests, enhancing testing efficiency.
  • NuGet Security Audits: Security audits are now performed by default on both direct and transitive package references, increasing security for dependencies.
  • Terminal Logger: The terminal logger is enabled by default, providing a summary of failures and warnings at the end of builds for better visibility.

ASP.NET Core Improvements

  • Enhanced Security: ASP.NET Core applications are more secure by default with new APIs for authentication and authorization.
  • Ahead-of-Time (AOT) Compilation: Expanded support for AOT compilation allows for faster startup times and reduced memory usage in web applications.
  • Optimized Static File Handling: Improved handling of static files like JavaScript and CSS at build time includes automatic fingerprinting for better cache management.
  • Blazor Enhancements: New templates for Hybrid and Web apps, improved component render mode detection, and a better reconnection experience with server rendering.

Language Features

  • C# 13 Enhancements: New language features improve code readability and reduce boilerplate. This includes features like required properties that enforce essential assignments during object initialization.

F# 9 Features

  • Nullable Reference Types: Support for nullable reference types enhances type safety.
  • New Language Constructs: F# 9 introduces new constructs such as discriminated union properties and improved pattern matching capabilities.

Additional Libraries and Tools

  • System.Text.Json Improvements: New options for customizing JSON serialization settings enhance flexibility in data handling.
  • Cryptography Enhancements: Support for hardware-accelerated cryptographic algorithms improves performance for hashing and encryption tasks.

Machine Learning Updates

  • ML.NET Enhancements: The machine learning framework now includes more pre-built models and simplified integration processes, making it easier to implement machine learning functionalities in applications.

These features collectively aim to enhance developer productivity, improve application performance, and provide robust security measures in .NET 9. As a standard-term support (STS) release, .NET 9 will be supported for 18 months, making it a significant update for developers focusing on cloud-native applications.