Announcing .NET 9: The ultimate evolution in modern development

The .NET team has officially launched .NET 9, the most advanced version of the development framework to date. With thousands of improvements in performance, security, and functionality, this release is designed to solidify its position as the ultimate tool for building modern, scalable, AI-driven applications.

Available for download starting today, .NET 9 includes updates for Visual Studio 2022 and the C# Dev Kit in Visual Studio Code, alongside new features that promise to revolutionize multi-platform app development.

Unmatched Performance

.NET 9 is the most efficient release of the platform so far, featuring over 1,000 performance-related enhancements across runtime, workloads, and languages. Key highlights include:

• Improved Garbage Collection (GC): The Server GC is now more adaptive, dynamically adjusting to an application’s memory needs instead of solely relying on system resources. This is especially beneficial for applications running in multi-core or cloud environments.
• Optimized LINQ and System.Text.Json: Methods like Take and DefaultIfEmpty are up to 10 times faster in common scenarios, while JSON operations show performance gains exceeding 50%.
• Vectorization Enhancements: Better support for Arm64 SVE and AVX10 architectures, along with accelerated runtime loops via RyuJIT.

The TechEmpower benchmark highlights a 15% increase in requests per second (RPS) and a 93% drop in memory usage, underscoring the impact of these improvements.

.NET Aspire: Building Production-Ready Apps

.NET Aspire continues to evolve as a complete toolkit for developing observable, production-ready applications. The latest version offers:

• Enhanced Resource Control: Developers can start or stop resources directly from the telemetry dashboard, keep containers alive between debug sessions, and use new APIs like WaitFor for better resource management.
• Simplified AI Integrations: Collaborations with OpenAI, Milvus, and other partners make it easier than ever to infuse AI capabilities into .NET Aspire applications.
• Expanded Compatibility: Now supports Azure Functions in preview mode and streamlined deployments with Azure Container Apps.

Microsoft has also introduced a free course and a new certification to help developers get started with .NET Aspire, reinforcing its commitment to education and community building.

AI and .NET: A Thriving Ecosystem

.NET 9 enhances AI integration with new libraries and abstractions such as Microsoft.Extensions.AI and Microsoft.Extensions.VectorData. These tools simplify interactions with language models and vector data services, empowering developers to build advanced AI-driven applications.

Key enhancements include:

• Improved Tokenizers: Support for models like GPT, Llama, and Bert, as well as advanced tokenization algorithms such as Byte-Level BPE and WordPiece.
• GitHub Copilot Enhancements: Features like AI-assisted debugging, smarter variable inspection, and LINQ visualizations streamline coding workflows.

Companies like GitHub Copilot and Microsoft Copilot have already adopted these capabilities, showcasing the potential of AI-powered developer tools.

Enhancements in ASP.NET Core and Blazor

ASP.NET Core, .NET’s premier web development framework, introduces key updates in .NET 9:

• Static File Optimization: JavaScript and CSS files are fingerprinted during builds for efficient caching and deployment. Brotli compression further reduces download sizes.
• Blazor Enhancements: New APIs like RendererInfo allow runtime adjustments to component rendering, and Blazor Server now features a smoother reconnection experience.

For API developers, native OpenAPI support simplifies documentation generation and enhances performance optimization for Minimal APIs.

Multi-Platform Development with .NET MAUI

.NET MAUI continues to dominate cross-platform development, supporting Android, iOS, macOS, and Windows from a single codebase. New features in .NET 9 include:

• Advanced Controls: Updates to CollectionView and CarouselView for iOS and Mac Catalyst, along with community-driven enhancements to templates.
• Native Platform Integrations: Support for the latest OS versions and improved interop with native libraries via the Xcode Sync dotnet tool.

.NET MAUI’s growing adoption reflects its success, with developer usage up 30% and a doubling of apps published to the Google Play Store in the past year.

C# 13 and F# 9: Enhanced Programming Languages

C# 13 introduces features to streamline coding, such as:

• Collection Expressions with params: Support for collection types beyond arrays in method signatures.
• Improved Multithreading Support: New APIs like Lock enhance thread-safe programming.

F# 9 brings functional programming refinements, including optimized loops, better equality checks, and enhanced diagnostics for safer and more performant code.

Conclusion

The release of .NET 9 marks a milestone in modern software development, providing tools that combine unmatched performance, accessibility, and AI-driven capabilities. From web and mobile applications to enterprise solutions, this release promises to be an indispensable resource for developers worldwide.

Downloads (Windows, Linux and Mac OS) and detailed documentation for .NET 9 are now available on Microsoft’s official website. With its broad array of improvements, .NET 9 positions the developer community to tackle the challenges of an ever-evolving tech landscape.