November 2025, Revisited: .NET 10 LTS, C# 14, and a New Visual Studio

This post is part of our Three-Year Retrospective series: thirty-six posts, one per month, looking back at what actually mattered in software engineering. This one covers November 2025.

In the second week of November 2025, timed to .NET Conf, Microsoft shipped its entire platform stack at once: .NET 10 on November 11 as a long-term support release (supported through November 2028), C# 14 alongside it, and Visual Studio 2026 in the same news cycle. For enterprise .NET shops — the most upgrade-cadence-conscious audience in software — this was the release that mattered, because .NET 8's support clock was now visibly running out and .NET 10 was the next LTS landing zone.

An LTS built on two years of runtime work

LTS releases inherit the odd-numbered experiments, and .NET 10 inherited good ones. The JIT picked up better devirtualization and inlining, improved stack allocation of small arrays, and broad AVX10.2 groundwork; ASP.NET Core and the libraries took their usual pass of allocation-shaving. The cumulative effect — .NET 8 to .NET 10 — was the kind of double-digit throughput improvement on real services that makes an upgrade self-justifying.

The feature that generated the most conversation, though, was small: file-based apps. A single .cs file with #! support and inline package directives could now just run — dotnet run app.cs — and graduate to a full project later. C# finally had a scripting-friendly on-ramp, and C# 14 itself stayed in character with quality-of-life work: extension members (extension properties at last), the field keyword for auto-property backing fields, and null-conditional assignment.

Blazor's maturity release, MAUI's quality release

We described .NET 10 to our web-focused students as the release where Blazor stopped needing caveats. The work was unglamorous and exactly right: better diagnostics and tracing for circuits, smarter reconnection UX for Server, preloading and smaller bundles for WebAssembly, validation improvements, and a PersistentState model that made the render-mode transitions of .NET 8's unified model feel less like a trapdoor. Teams that had evaluated Blazor in its awkward adolescence and passed were, in our experience, genuinely surprised on re-evaluation.

.NET MAUI's release notes told their own story by what they emphasized: issue-count reductions, performance, and platform-version support rather than splashy features. After several years of credibility rebuilding, a deliberate quality release was the right move, and the framework's reputation among the teams we train improved accordingly — helped by XAML source generation and steady CollectionView work.

Visual Studio 2026: the IDE becomes an AI surface

Visual Studio 2026 — note the year-based name, and a faster update rhythm to go with it — was the first Visual Studio designed in the agentic era. The Fluent-refreshed UI and the genuinely large performance work (markedly faster solution loads on big codebases) would have carried a release on their own. But the positioning was unmistakable: Copilot woven through the editor, the debugger, and the profiler, with agentic workflows treated as a first-class way to use the IDE rather than a sidebar. Reactions in our classrooms split predictably — enthusiasm for the profiler-aware AI assistance, wariness about the growing assumption that an IDE session includes a model. Both reactions were reasonable; the direction was inevitable either way.

Looking back from June 2026

The migration wave arrived on schedule. With .NET 8 and 9 both reaching end of support in November 2026, the first half of this year has been one long .NET 10 upgrade season, and it has been pleasantly boring — the LTS-to-LTS path from 8 to 10 is among the smoothest major upgrades in the ecosystem's history. Blazor's no-caveats status held; we now see it as the default choice for new internal line-of-business web apps in .NET shops. Visual Studio 2026's monthly-cadence updates have steadily deepened the agentic integration, which no longer reads as a bet so much as a description of how .NET development now works.

If your team is riding the LTS wave, Build .NET 10 Web Apps with Blazor covers the mature render-mode model and the .NET 10 improvements hands-on, and Build Cross-Platform Apps with .NET MAUI does the same for teams taking MAUI's quality-era release onto mobile and desktop.