On November 11, 2025, Microsoft officially launched .NET 10, the latest Long-Term Support (LTS) release of its unified development platform. Supported with updates and security patches until November 10, 2028, this version is engineered to be the fastest and most capable .NET yet, delivering foundational improvements across performance, developer productivity, and artificial intelligence.

Described by Microsoft as the result of a year-long effort involving thousands of contributors, .NET 10 strengthens its role as a versatile platform, equally adept at powering cloud-native microservices, intelligent AI agents, and traditional desktop applications. This release provides a stable, three-year foundation upon which teams can confidently build the next generation of software.

.NET 10 delivers significant, measurable gains in execution speed and efficiency, building upon its reputation for high performance. A key focus has been optimizing the Just-In-Time (JIT) compiler with better method inlining, advanced devirtualization techniques, and enhanced stack allocation strategies. These low-level improvements allow everyday C# and F# code to run faster with less memory overhead.

The runtime also introduces cutting-edge hardware acceleration support, future-proofing applications for next-generation silicon. This includes support for AVX10.2 on new Intel processors and Arm64 SVE (Scalable Vector Extension) for advanced vectorization on Arm chips. Specific optimizations, such as improvements to Arm64 write-barriers, are credited with reducing garbage collection (GC) pause times by 8-20% on that architecture. Furthermore, NativeAOT (Ahead-of-Time) compilation has been refined to produce even smaller, quicker-starting self-contained executables.

Accompanying .NET 10 are major updates to its primary languages, designed to make code more expressive, concise, and enjoyable to write.

C# 14 introduces several quality-of-life enhancements that reduce boilerplate. A standout feature is field-backed properties, which use a new field keyword to directly access a property's auto-generated backing field, simplifying the implementation of custom getters and setters.

The language also gains powerful extension members, allowing developers to add not just methods, but also properties, static members, and operators to existing types—including interfaces—through a new extension block syntax. Other notable additions include null-conditional assignment (?.=), parameter modifiers in lambda expressions, and support for user-defined ++ and -- operators.

F# 10 is a refinement release centered on clarity and performance. It introduces scoped warning suppression for precise control over compiler diagnostics, access modifiers on auto property accessors, and the use of and! in task expressions for concurrently awaiting multiple tasks. These enhancements streamline the development experience for the F# community.

Recognizing the transformative role of AI, .NET 10 integrates new frameworks and optimized libraries for building intelligent applications.

A centerpiece is the Microsoft Agent Framework, which provides standardized patterns for constructing "agentic" AI systems. It combines capabilities from Semantic Kernel and AutoGen into a unified model for creating single agents or orchestrating complex multi-agent workflows. The framework includes built-in support for OpenTelemetry and the Model Context Protocol (MCP), facilitating the integration of external tools and data sources.

For computationally intensive AI workloads, such as running Small Language Models (SLMs) locally, .NET 10 enhances its numerical foundations. The System.Numerics.Tensors library receives new optimizations, offering high-performance, SIMD-accelerated operations for tensor and vector math, which are fundamental to machine learning and AI inference tasks.

As a major LTS release, .NET 10 introduces several breaking changes that teams must account for in their migration strategy.

One of the most impactful changes is in ASP.NET Core: endpoints using cookie authentication that are identified as APIs will no longer automatically redirect to login pages. Instead, they will correctly return 401 Unauthorized or 403 Forbidden status codes. Several legacy patterns have also been marked obsolete, including IWebHostBuilder/WebHostBuilder (in favor of WebApplicationBuilder), IActionContextAccessor, and Razor runtime compilation (replaced by tooling-based Hot Reload).

Other important changes include:

Regarding tooling, Visual Studio 2026 is recommended for the best experience with .NET 10, but developers can continue using Visual Studio 2022 to build and run .NET 10 applications.

.NET 10 solidifies its position as a comprehensive, high-performance platform ready for contemporary challenges. By coupling a three-year LTS commitment with leaps in raw speed, modern language features, and first-class support for AI and cloud-native patterns, it offers a compelling foundation for enterprise investment.

Whether you are building responsive web APIs with ASP.NET Core, intelligent multi-agent systems, or efficient cross-platform desktop applications, .NET 10 provides the stability and cutting-edge capabilities required. For teams planning their technology roadmap, upgrading to this LTS version is a strategic move to secure a supported, powerful, and productive development environment through 2028 and beyond.