# Microsoft releases .NET 11 with C# unions and revised development tooling

_Published Tuesday, November 10, 2026 at 11:40 AM EST · Products · Latest · Tier 2 — Notable_

![Microsoft releases .NET 11 with C# unions and revised development tooling — Primary](https://devblogs.microsoft.com/dotnet/wp-content/uploads/sites/10/2026/11/announcing-dotnet-11-scaled.webp)

Microsoft released .NET 11 with two years of support, adding C# 15 union types, runtime changes and development tools. Union types let developers declare a set of possible value types and have the compiler check that switch expressions handle them.

The SDK enables a Native AOT command-line host and keeps an MSBuild server warm between invocations to reduce startup overhead. .NET MAUI makes CoreCLR its default runtime across platforms, while the SDK adds a template for exposing tools to AI applications through the Model Context Protocol.

Runtime Async remains in preview, and the Blazor AI components remain experimental and prerelease. .NET 10 remains a supported long-term-support option.

## Sources

- [devblogs.microsoft.com](https://devblogs.microsoft.com/dotnet/announcing-dotnet-11/)

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Canonical: https://techandbusiness.org/newswire/qMKpaLry1Y8skIQwTv6IoA
Published: 2026-11-10T16:40:29.853Z
Story chronology: 2026-11-10T16:11:00.000Z
Retrieved: 2026-11-10T19:11:20.005Z
Publisher: Tech & Business (techandbusiness.org)