A faster, lighter C# Dev Kit
Microsoft .NET Blog C# Dev Kit has been rebuilt to open solutions in about a second and run on a fraction of the memory, and this post walks through what changed for you.
Topic
.NET
News about .NET, C#, and ASP.NET Core releases and engineering.
Image: Microsoft .NET Blog UWP and WinUI 3 apps: UI testing with MSTest
Microsoft .NET Blog Learn how to test UWP and WinUI 3 apps with MSTest and Microsoft.Testing.Platform across packaged, unpackaged, and AppContainer hosts.
Image: Microsoft .NET Blog Build Agentic UI with the new Blazor AI components
Microsoft .NET Blog Build Agentic UI with the new Blazor AI components for streamed content, tools, approvals, shared state, and generative experiences.
Image: Microsoft .NET Blog AG-UI Protocol now has a first-class .NET SDK
Microsoft .NET Blog The new AG-UI .NET SDK enables .NET services to expose and consume interoperable agent endpoints using Microsoft.Extensions.AI.
Image: Microsoft .NET Blog Microsoft is updating its author-signing certificate starting September 23, 2026
Microsoft .NET Blog Starting September 23, 2026, Microsoft is updating the author-signing certificate used for NuGet packages. Customers using trusted signer policies or certificate fingerprint verification should add the new certificate as soon as possible.
Image: Microsoft .NET Blog Creating a memory dump in C#
Microsoft .NET Blog Learn how to create a memory dump in C# to capture the state of your application for debugging purposes.
Build Your Own AI Agent Harness in C#, the MafClaw Live Series
Microsoft .NET Blog I am building a complete C# agent live, from a single call around an IChatClient to a production-ready, observable, governed agent, using the Microsoft Agent Framework harness in a 4-part Microsoft Reactor series.
Performance Improvements in .NET 11
Microsoft .NET Blog Take a tour through hundreds of performance improvements in .NET 11.
Share your .NET story with the community
Microsoft .NET Blog Share how your team uses .NET to solve real problems and help us bring more community stories to .NET Conf 2026 and other .NET channels.
Use C# unions and closed hierarchies in ASP.NET Core
Microsoft .NET Blog Learn how C# unions and closed hierarchies work with System.Text.Json across ASP.NET Core Minimal APIs, MVC, SignalR, Blazor, and OpenAPI.
runtime .NET 10.0.12
Microsoft .NET Blog Release What's Changed [release/10.0] Source code updates from dotnet/dotnet by @dotnet-maestro[bot] in https://github.com/dotnet/runtime/pull/131201 [release/10.0] Fix EH - throw from catch in UnmanagedCallersOnly by @janvorli in https://github.com/dotnet/runtime/pull/131467…
runtime .NET 9.0.20
Microsoft .NET Blog Release What's Changed [release/9.0-staging] Migrate devdiv/dotnet-core-internal-tooling to WIF service connection by @github-actions[bot] in https://github.com/dotnet/runtime/pull/130917 [automated] Merge branch 'release/9.0' => 'release/9.0-staging' by @github-actions[bot] in…
runtime .NET 8.0.31
Microsoft .NET Blog Release What's Changed [release/8.0-staging] Migrate devdiv/dotnet-core-internal-tooling to WIF service connection by @github-actions[bot] in https://github.com/dotnet/runtime/pull/130915 [automated] Merge branch 'release/8.0' => 'release/8.0-staging' by @github-actions[bot] in…
runtime .NET 10.0.11
Microsoft .NET Blog Release What's Changed [release/10.0] Fix TypeLoadException in GetMarshalAs when SafeArray has zero-length user-defined type name by @AaronRobinsonMSFT in https://github.com/dotnet/runtime/pull/129899 [release/10.0] Pass correct search path to DllImportResolver for default flags…
runtime .NET 9.0.19
Microsoft .NET Blog Release What's Changed [release/9.0-staging] Wait to complete the test before releasing the agile reference. by @github-actions[bot] in https://github.com/dotnet/runtime/pull/129430 [release/9.0-staging] Update dependencies from dotnet/runtime-assets by @dotnet-maestro[bot] in…
runtime .NET 8.0.30
Microsoft .NET Blog Release What's Changed [release/8.0-staging] Update dependencies from dotnet/icu by @dotnet-maestro[bot] in https://github.com/dotnet/runtime/pull/129375 Surface scheduled outerloop Helix work item failures as warnings by @mmitche in https://github.com/dotnet/runtime/pull/129629…
runtime .NET 10.0.10
Microsoft .NET Blog Release What's Changed [release/10.0] Source code updates from dotnet/dotnet by @dotnet-maestro[bot] in https://github.com/dotnet/runtime/pull/128197 [release/10.0] Fix assertions generated by optCreateJumpTableImpliedAssertions by @github-actions[bot] in…
runtime .NET 9.0.18
Microsoft .NET Blog Release What's Changed [release/9.0-staging] Update dependencies from dotnet/cecil by @dotnet-maestro[bot] in https://github.com/dotnet/runtime/pull/125099 [release/9.0-staging] Update dependencies from dotnet/runtime-assets by @dotnet-maestro[bot] in…
runtime .NET 8.0.29
Microsoft .NET Blog Release What's Changed [release/8.0-staging] Fix loop hoist memory-dependence tracking by @AndyAyersMS in https://github.com/dotnet/runtime/pull/128381 [release/8.0-staging] Update dependencies from dotnet/runtime-assets by @dotnet-maestro[bot] in…
runtime .NET 10.0.9
Microsoft .NET Blog Release What's Changed [release/10.0] [NET] Fix docker compose. by @ManickaP in https://github.com/dotnet/runtime/pull/126473 [release/10.0] Force MetaDataGetDispenser to be linked into singlefilehost by @github-actions[bot] in https://github.com/dotnet/runtime/pull/127237…
