Microsoft introduces .NET 9, with performance improvements, new AI integrations and support for multi-platform development. The update includes changes to runtime and programming languages ​​such as C# and F# and provides expanded functionality for cloud and AI-based applications.

Microsoft is launching .Net 9, following a preview that began earlier this year. With .NET 9, Microsoft introduces more than a thousand performance improvements, including dynamic optimization of the server garbage collector (GC). This optimization focuses on more efficient memory management, which is particularly beneficial for cloud applications with varying memory usage.

Users can still use the classic server GC implementation for testing. This results in an increase in processing capacity and lower memory usage. Additionally, the runtime and JIT compiler are optimized for new hardware and instruction sets, ensuring faster code execution.

Improvements have also been made to the base libraries, for example in System.Text.Json, where the JSON processing methods are now more efficient and save storage space. LINQ methods have been adjusted for faster performance on empty arrays and lists, with specific optimizations for common operations.

AI integration and new tools for developers

.NET 9 addresses the growing demand for AI support with the introduction of Microsoft.Extensions.AI and Microsoft.Extensions.VectorData. These libraries provide developers with standardized interfaces for AI services such as language models and vector storage. Tokenization algorithms have also been improved, with expanded support for common models such as GPT and BERT, making it easier for .NET developers to integrate AI capabilities.

GitHub Copilot provides additional productivity tools for .NET developers with features such as AI-driven debugging, improved code completion, and code troubleshooting support. Visual Studio 2022 (version 17.12) has been updated with integration for .NET Aspire, cloud capabilities, and new analysis tools designed specifically for C# 13.

Multiplatform

With .NET 9, .NET MAUI remains a core option for cross-platform application development with improved performance and new templates. The MAUI framework supports the latest operating system versions and allows developers to use a single codebase for Android, iOS, macOS and Windows. A contribution from component developer Syncfusion has also been added, with pre-built elements for faster app development.

Blazor, the web and hybrid app framework, has seen improvements in runtime performance and now offers better support for interactive rendering. ASP.NET Core has been updated with static file optimizations, enhanced caching, and a new OpenAPI integration that automatically generates documentation for APIs.

.NET 9 and the updated Visual Studio 2022 v17.12 are now available for download.