Microsoft has released .NET 9, a major upgrade to its open-source software development platform. This release features significant performance enhancements and new capabilities for building AI-enabled applications. It includes over 1,000 performance-related changes across runtime, workloads, and languages, along with more efficient algorithms for code generation. Microsoft has made integrating AI into .NET apps easier by building out a smart components ecosystem. The release also includes new features in the C# and F# programming languages, making it easier and safer for developers to write code.