.NET 10
Overview
.NET 10 was released on 11th November during .NET Conf 2025 and allows you to build any app with tools and libraries you need for games, mobile, cloud, agent with AI or ML, web, desktop and IoT using Azure, NuGet, Aspire and Visual Studio with GitHub, Windows, Linux and macOS. .NET 10 is the supercharged .NET SDK built for todays and tomorrows workloads that enable developers to leverage .NET, the free open-source cross platform for developing modern applications and services. Details of the announcements around .NET 10 along with Visual Studio 2016 and other sessions in the agenda covering a variety of topics from a range of speakers including many from the community at .NET Conf 2026 can be found at dotnetconf.net.
.NET 10 has over seven million active users and since it went open source there have been over 290,000 pull-requests merged with over 23,000 PRs contributed to .NET 10 alone both of which from over 68,000 contributors and .NET is one of the top five high velocity open-source software projects. .NET helps reduce costs and help's power Microsoft services at scale including Microsoft Copilot, Xbox and Bing who have seen the lowest latency on 90% of their requests and Microsoft Copilot uses almost the entire .NET stack to build their AI powered assistant and Microsoft Copilot Studio is a Blazor WebAssembly application plus companies from all over the world from small businesses to large enterprises use .NET.
.NET 10 enables faster and more elegant code that is extensible with C# 14 which delivers industry leading performance with improvements to help apps launch quicker, run smoother and scale effortlessly. C# features syntax for extension members to enable extension properties to be defined, field-backed properties with a property accessor without needing to define an explicit backing field and null-conditional member access operator for assignment to potentially null values. .NET 10 enables developers to build more secure and future ready apps with confidence with modern features plus .NET 10 is a long-term support or LTS release which will mean it will be supported for three years.
.NET 10 isn't just a feature update but a definitive performance boost with many new features including runtime improvements, just-in-time compiler optimisations, improved garbage collector and support for cutting-edge silicon along with features such a single-file based apps with publish support and native AoT, first-class support for Model Context Protocol along with new APIs for cryptography, globalisation, collections, diagnostics, new JSON serialisation options and networking enhancements. .NET 10 also has security features and cryptography enhancements including Windows Cryptography API and Next Generation support for Post-quantum Cryptography.
Aspire
Aspire is the code-first, extensible and observable way to define and deploy your stack in code using C# that is type-safe, readable and debuggable to run locally then shift to real cloud services that can use integrations that allow you to plug into any local or remote code or service and Aspire can bring common patterns but also be able to model anything. Aspire allows you to see your entire stack running in one place with logs, endpoints, environment variables and even full open telemetry. Aspire is no longer .NET Aspire but is still built in .NET that is extensible with integrations and Aspire 13 is the biggest release yet alongside .NET 10 with a unified infrastructure where you can deploy .NET, JavaScript, Python that supports debugging, container-deployment and auto-generated Dockerfiles.
Aspire enables a modern development experience with CLI enhancements, single-file AppHost support leveraging the single-file application support in .NET 10 along with quicker onboarding with seamless build and deployment plus static file support and robust deployment parallelism. Aspire also provides enterprise-ready support for infrastructure and services with flexible connection strings and language agnostic certificate trust with a whole host of functionality provided out of the box that is easily extendable to meet any additional requirements. Aspire also supports .NET MAUI where you can have an app running in an emulator and alongside running with other dependent webservices and allow for deployment seamlessly from client to cloud. Find out more about Aspire at aspire.dev.
Agents & AI
.NET app modernisation has many challenges which can include dependency conflicts, identifying these and researching alternatives can often be a guessing game and result in a significant re-architecture plus deprecated APIs and identifying these and learning how to update them is not immediately clear and can introduce issues and it can take too long to refactor. However the benefits of modernising apps includes reducing security risks by staying up to date with security patches, runtime libraries and more along with improved performance and scale where can access a cross-platform runtime that delivers an order-of-magnitude gain in performance though the years of performance investments plus applications can gain access to modern APIs, improved tooling and be able to take advantage of cloud-native architectures such as Azure.
GitHub Copilot app modernisation can assist with this process, where it isn't just about staying current but can help set you up for success and cloud-native features, where you can quickly upgrade .NET versions and associated frameworks using AI agents to increase app performance, perform end-to-end code assessment and remediation for apps or moving to Azure. You could upgrade to .NET 10 or use AI agents to automatically make code changes for moving to Azure app platform services or prepare for a cloud migration in a less stressful way that is build into Visual Studio 2026 and GitHub Copilot which makes it possible to upgrade applications seamlessly and often older applications lack unit tests so GitHub Copilot for testing can help automate repetitive testing tasks and turn unit testing into a productivity boost.
.NET enables developers to build intelligent applications intelligently to create agentic .NET apps that are infused with AI-powered agents for cloud, web, desktop, mobile, games, and IoT alongside agentic DevOps for AI-powered agents that operate as a member of your dev team in Visual Studio, Visual Studio Code, GitHub and Azure. Agents work with a large language model with instructions from input such a system events, user and agent messages along with being able to perform tool calls including retrieval, actions or memory plus output including agent messages and tool results. Business is full of ambiguity and that's where large language models and agents come in that can figure their way around detours and get the job done to bring a kind of human-like reasoning.
Microsoft Agent Framework unites Semantic Kernel and AutoGen frameworks for a reliable, flexible and developer friendly API using Microsoft.Extensions.AI to simplify agent development and deliver flexibility to build save, responsible and robust AI powered applications with the latest version of Microsoft Agent Framework being available in Public Preview. Model Context Protocol allows large language models to use tools and request resources beyond their initial training and with the MCP C# SDK .NET developers can build MCP services that expose functionality to agentic apps, GitHub Copilot and more with the MCP C# SDK being used by many projects in Microsoft that support MCP that can be exposed and used by MCP clients.
ASP.NET Core
ASP.NET Core is the complete, modern web framework for minimal APIs for fast HTTP APIS, SignalR for real-time services along with gRPC for backend RPC calls, build-in and custom middleware along with Kestrel which is a high-performance HTTP server. ASP.NET Core is trusted by millions of developers and powers the world's largest services with industry leading performance and is the foundation of many modern cloud and AI powered applications including Microsoft 365, Bing and Xbox. .NET 10 with ASP.NET Core makes it easier to build secure apps with targeted performance improvements and security improvements such as support for passkeys which are cryptographic credentials that replace traditional passwords and are phishing-resistant, easy-to-use and secure by design.
ASP.NET Core in .NET 10 features improved app observability and diagnostics to enable monitoring of a production service or gather metrics that can be used in Aspire or gather information to diagnose issues. ASP.NET Core includes improved API JSON deserialisation performance along with performance improvements with faster requests per second and reduced memory usage including releasing memory from Kestrel memory pool as before Kestrel would grow a memory pools as needed but would hold onto this even after traffic has dropped but now memory will be trimmed overtime which will reduce your app's footprint resulting in better scaling, lower idle costs and smarter resource usage.
ASP.NET Core in .NET features minimal API validation and server-sent events along with support for OpenAPI 3.1, XML documentation comments-based OpenAPI descriptions and support for emitting OpenAPI documents in YAML format along with improvements to JSON Patch and generating the correct unauthorised responses for APIs for a view in an application to perform a redirection or the appropriate response to a call to an API.
Blazor
Blazor enables modern web UI development with C# which is .NET from the frontend to the backend enabling client and server-side rendering with security features built-in and reusable web components with HTML and CSS with built-in and a marketplace of third-party extensions and components optimised for performance. Blazor is even better with .NET 10 with simplified security including support for Passkeys in ASP.NET Core with Blazor template support for Passkeys plus a new scaffolder for Entra AI authentication. Observability and diagnostics in Blazor include metrics, traces and diagnostic tools for Blazor WebAssembly and other Blazor specific metrics. Blazor features improved performance for startup and runtime with Blazor framework scripts that are fingerprinted, compressed and cached plus Blazor Assembly resources are preloaded including runtime scripts along with faster runtime execution and rendering.
Blazor improvements are reflected in Microsoft Copilot Studio which is the platform for building and managing AI agents and automation which has maintained a consistent user experience by running existing C# code directly in the browser which leverages .NET WebAssembly ahead-of-time compilation for improved performance along with improvements from using the latest version of .NET with .NET 10, which aims to delight developers and address top pain points and feature gaps such as improving hot reload to make it faster, enhanced form validation, consistent navigation behaviour across render modes and more along with adding Blazor state persistence which delivers simplified prerendered state persistence with a new declarative model for prerendering persistent state.
Blazor state persistence in .NET 10 also can automatically persist circuit state for improved reliability where can persist the circuit state on the server when a client is disconnected for an extended period such as when a user switches tabs or swipes away from a browser app on a mobile device. Blazor state persistence can also persist idle circuits for betting scalability with APIs by proactively pausing and resuming circuits when needed such as when a server is restarting or a client is no longer visible by implementing an app specific policy in Blazor.
.NET MAUI
.NET MAUI is for cross-platform applications in .NET, where improvements in .NET 10 has been for quality and performance to make runtime and debugging faster along with simplicity to make XAML easier to work with and make it easier to maintain apps and adopt more patterns such as using Aspire. New features in .NET for .NET MAUI include global namespaces for XAML to make it more legible and available as a preview feature will be implicit namespaces which will allow removal of boilerplate XAML at the head of every file for a cleaner more legible file plus language services and support coming with XAML source generation using Roslyn source generation to get faster debug runs, consistent UI on release and ability to debug generated UI code.
.NET MAUI features a new API for safe area on mobile devices to accommodate cut-outs in the screen to allow edge-to-edge content or to ensure content obeys safe areas on Android and iOS. Hybrid apps in .NET MAUI with JavaScript frontends include fit-and-finish work along with better exception handling and new hooks for intercepting web requests for HybridWebView and BlazorWebView. Aspire orchestration in .NET MAUI means you can define your stack including frontend, database, APIs and containers with support for configuration, observability and deployment plus leverage diagnostics to monitor your .NET MAUI application performance in Aspire.
Modern Windows Development
Windows development is a large ecosystem with over a billion devices with tools and libraries including Terminal, Windows Subsystem for Linux, WinGet and Power Toys and developers can leverage Windows App SDK, WinUI, Windows ML and Windows AI APIs to build great experiences on Windows with the aid of a variety of resources including sample galleries, design guidance and more. WinUI Gallery is an encyclopaedia of knowledge to help build applications and everything you need from the Fluent Design system to build great Windows experiences and use resources in your application to get the same styling in Windows Presentation Foundation. Windows Community Toolkit is a gallery application showcasing a collection of open-source helpers, extensions and controls from the community that can also be used to build great Windows apps.
WinUI is being open sourced with the rationale to enable true community collaboration to increase transparency and accelerate innovation where the benefits include reduced friction and where can inspect, debug and even contribute fixes to enable faster resolution of bugs and feature gaps to allow members of the community to empower thousands of other developers around the world. AI Dev Gallery is where you can use models and bring them to your device to run on CPU, GPU and NPU locally and democratise the AI experience for Windows for text, images, audio or code. Microsoft Foundry local is a new preview API which provides an easy-to-use storage for local models on your device so can share a central model store, so models don't need to be stored in multiple places and save space on a user's computer.
Windows App SDK is now using semantic versioning with a release schedule for major releases yearly or with breaking changes, minor releases monthly with additive updates and patch releases for bug or performance fixes. Windows App SDK also support pick-and-chose with NuGet meta packages so you can include what you require or everything from Windows App SDK which means you can trim down and only include the packages you need and can help reduce package sizes by up to 50% depending on the functionality you need to include.
Windows Forms
Windows Forms with .NET 10 includes enhanced dark mode support including system-wide dark mode detection and automatic theming along with property for runtime queries to determine if dark mode is enabled and system colours automatically adapt to dark or light themes and can set which to use on startup. Windows Forms with .NET 10 also includes customisation APIs to allow the window border colour to be customised along with the title bar background and text colour plus can set the window of an application to have rounded, small rounded or no rounding as well as being able to hide a window or content from features such as Recall or Copilot in Windows if handling sensitive information.
Windows Forms in .NET 10 also includes proper async and await support for cross-thread user interface updates and can use async overloads to avoid fire and forget as well as new Windows Forms analysers that can catch common mistakes at compile time plus there is ShowAsync for non-blocking display of forms and ShowDialogAsync for async and await with modal dialogs.
Summary
.NET 10 is a supercharged SDK that is designed for today's and tomorrow's workloads to build or modernise applications to use the latest features with performance improvements and leverage new functionality. .NET developers can also enhance their development using agents in GitHub Copilot or create agents using it with agentic AI providing functionality that could leverage Model Context Protocol to perform actions. .NET applications can be created for web and cloud using ASP.NET Core and Blazor, cross-platform with .NET MAUI which can be orchestrated and deployed with Aspire or create native Windows applications with Windows App SDK and WinUI, Windows Presentation Foundation or Windows Forms.
You can visit dot.netto get started, learn more or to download the latest SDK for .NET 10 or you can listen about .NET 10 on the RoguePlanetoid Podcast.