.NET 10 Preview 3 Brings Smarter C#, Stronger Libraries, and WebAssembly Gains
Microsoft continues to push the boundaries of its cross-platform development ecosystem with the release of .NET 10 Preview 3. This latest milestone introduces a mix of language enhancements, runtime improvements, and expanded library capabilities that lay the groundwork for a more robust development experience across native, web, and AI-powered applications. Notable highlights include new C# extension features, improvements to Blazor WebAssembly, and safer support for ahead-of-time (AOT) compilation scenarios.
Released on April 10, Preview 3 follows closely behind Preview 2 in March and the initial release in February, indicating a steady development cadence toward .NET 10’s anticipated general availability in November. Developers can grab the latest preview from the official .NET site and begin testing the new features in their environments.
A key technical improvement is the addition of an AOT-safe constructor for the ValidationContext class. This change addresses a long-standing limitation where the use of reflection during validation made native AOT compilation risky or error-prone. With this safer constructor, developers targeting AOT scenarios—such as building native apps with performance and size constraints—can now rely on ValidationContext without encountering compiler issues.
The standard library also sees meaningful updates, particularly for machine learning workloads. ML.NET’s LightGBM trainer now includes deterministic training options, giving developers tighter control over training behavior for reproducibility and debugging. On the language side, C# 14 continues to evolve, with extension support expanded to include static methods, static properties, and instance properties—setting the stage for more expressive and modular code. Microsoft has hinted at even more extension support in future previews, signaling that .NET 10 will be as much about modernizing developer ergonomics as it is about runtime efficiency.