C# 15

Microsoft released .NET 11 at .NET Conf 2026 as a Standard Term Support version with two years of support. The release adds hundreds of runtime and base-library performance optimizations and deepens AI tooling: the SDK ships MCP server templates, companion AI libraries and an agent framework cover model access, tool calling and workflow orchestration, and Blazor gains experimental AI UI components. C# 15 introduces union types, and .NET MAUI now defaults to the CoreCLR runtime.

Microsoft has released .NET 11, spanning C# 15, ASP.NET Core, .NET MAUI and Windows development, with hundreds of runtime optimizations and faster SDK tooling. The release emphasizes AI-powered development and agentic capabilities, letting developers build web, cross-platform and AI applications with less overhead.