トピックス
.NET October 2026 Out-of-Band Security Updates - .NET Blog
https://devblogs.microsoft.com/dotnet/dotnet-october-2026-oob-security-updates/
Visual Studio October Update – Compare Commits to Your Code, Resolve Conflicts in Bulk, Keep Coding - Visual Studio Blog
Blazor Welcomes Open-Source Contributions from Infragistics - .NET Blog
https://devblogs.microsoft.com/dotnet/blazor-welcomes-infragistics/
アーティクル、スライドなど
.NET ThreadPoolを測る：JITウォームアップとスレッド供給を分けて考える - Qiita
https://qiita.com/tomokusaba/items/66cdb36207bc5264d3fc
OSV-Scanner-MCP v0.16.0: .NET(NuGet)に対応してみた - Qiita
https://qiita.com/tedorigawa001/items/ff7b993a429cbbf29d01
.NET 8/9は11月10日でサポート終了、.NET 11は同日GA — AIと走り切った移行メモ
https://zenn.dev/jodycraft/articles/dotnet8-eol-dotnet11-ga-migration
dotnetupで複数バージョンのdotnetで開発する - Qiita
https://qiita.com/kashin777/items/2c38b1c7f7e9f56d68ed
Keep your investigation between sessions - Visual Studio Blog
https://devblogs.microsoft.com/visualstudio/keep-your-investigation-between-sessions/
「どの動画を一番見ているか」を知りたくて、Windows のファイルアクセスを記録・集計するツールを作った - Qiita
https://qiita.com/nuts_i77/items/34b1f6d5bc2f6effa3ee
【FFmpeg×C#】画像変換を11倍高速化した一括処理と、Ubuntu 24（FFmpeg 6.1）のパイプ出力でWebPが壊れるバグを直した話 - Qiita
https://qiita.com/nPonta/items/7c2d80c66c87172185d2
Windows で HDR の画面を撮ると白っぽくなる理由と、16bit で読んで直す方法
https://zenn.dev/hullspark/articles/9786d3fffef787
Preparing for Your Next Certification Could Start with Your Visual Studio Subscription - Visual Studio Blog
Playwright の E2E テストをプロキシ環境でローカル実行できるようにした (Vue.js + .NET) - Qiita
https://qiita.com/FumikaKoyama/items/744aebdb9934d4b8d1fb
How to Loop Through a List in C#: Every Way, Benchmarked
https://khalidabuhakmeh.com/posts/how-to-loop-through-a-list-in-csharp/
Microsoft.UI.Reactorを触ってみる - Qiita
https://qiita.com/is0263rf/items/12a27959bc876b777e9c
A Free .NET Profiler for VS Code: CPU, Memory and Leaks in C# and F#
https://sharplsp.dev/blog/dotnet-profiler-vs-code-csharp-fsharp/
Text to 3D, 100% in the browser: TRELLIS.2 on WebGPU from C#
https://dev.to/lostbeard/text-to-3d-100-in-the-browser-trellis2-on-webgpu-from-c-21d3
Are You Getting Everything You Can from Your Visual Studio Subscription? - Visual Studio Blog
https://devblogs.microsoft.com/visualstudio/what-should-we-blog-about-next/
【C#】ビットパーフェクト音楽プレーヤー PlayMuse を NAudio 3.3 にバージョンアップしてみた
https://zenn.dev/kerobot/articles/3dbea3af69a50e
DuckDB.NET 1.5.6.1: Reading Data Up to 12× Faster | Giorgi Dalakishvili
https://www.giorgi.dev/database/duckdb-net-1-5-6-1-data-reader-performance/
neue cc - C# Kaigi 2026「C#の現在地 進化の歴史と、AI時代の.NET Everywhere」, MessagePack for C# v4 preview.1
https://neue.cc/2026/10/23_csharpkaigi_msgpack_v4preview.html
ライブラリ、リポジトリ、ツールなど
hez2010/SatoriInsight
https://github.com/hez2010/SatoriInsight
Introducing Satori Insight, an open-source #dotnet memory profiler with real-time heap maps, GC events, pause stats, and session replay.
— skyake (@KaiSawano) October 26, 2026
Built with #AvaloniaUI. Supports Workstation, Server, and Satori GC on Windows, macOS, and Linux.https://t.co/647dycNNkX pic.twitter.com/weswqtdaUc
ツイート
Heads-up: C# Interactive has been removed from Rider as of 2026.3 EAP 7 and will not be included in the 2026.3 release. 🫡
— JetBrains Rider (@JetBrainsRider) October 26, 2026
Very few of you used it, and it had built up correctness and usability issues over time. We'd rather remove it than keep a feature that no longer meets our… pic.twitter.com/prLwcdvAKk
A single .md file with tips & tricks for high-performance .NET/C# code, mostly meant for AI, and mostly aimed at benchmarks against the crustaceans 🙃 https://t.co/Z6UB7q8eip (no unsafe!)
— EgorBo (@EgorBo) October 23, 2026
Contributions welcome if anything's missing, cc @axeng200 @ben_a_adams