F# Weekly #19, 2025 – How F#py is your C#?

Welcome to F# Weekly,

A roundup of F# content from this past week:

News

• Why we built our startup in C# – .NET Blog
• C# 14 – Exploring extension members – .NET Blog
• A Developer’s Guide to Build 2025 – Microsoft for Developers
• Announcing the General Availability of Managed Identities as Federated Identity Credentials in your Entra apps | Microsoft Entra Identity Platform
• Integration testing with Dapr and Testcontainers – ISE Developer Blog
• How Office Is Modernizing Their App Suite’s UI using Windows App SDK and React Native React Native
• Announcing the updated Teams AI Library and MCP support
• Fedora Linux is now an official WSL distro – Windows Command Line
• Nested App Authentication: Now available across Microsoft 365

This C# looks so F#py … #fsharp devblogs.microsoft.com/dotnet/why-w…

— Sergey Tihon 🦔🦀 (@sergeytihon.com) 2025-05-10T15:20:08.212Z

Videos

• .NET AI Community Standup – What’s Next for .NET and AI at Build 2025
• On .NET Live – Building Real-Time Web Applications with Akka.NET
• ASP.NET Community Standup – Automated browser testing with ASP.NET Core in .NET 10

Blogs

• F# vs C#: Best for Startups and Scale-ups
• Algebraic Data Types – by Desert Thunder – Pattern Matched
• Pulumi.FSharp.Extensions | Compositional IT
• The Shifting Computational Landscape and Returning Primacy of Compilers
• Exploring the new AI chat template

Highlighted projects

• simontreanor/FSharp.Finance.Personal: Personal finance functions written in F#
• afxres/binary: Serialization library for C# and F#.
• DragonFrai/Ferrum: library for working with dynamic Error types.
• HughPH/Box2D-dotnet-bindings: Box2D 3.x Bindings for dotnet (C#, F#, VB, …)

Active patterns make parsing so pleasant in #FSharp

— Robert Byrne (@kapitar.bsky.social) 2025-05-08T14:57:40.244Z

New Releases

• Ferrum 0.3.0
• Ferrum.Graphviz 0.3.0
• IcedTasks 0.11.8
• Numerics.NET.FSharp 9.0.3
• Hedgehog.Xunit 0.7.0
• SQLProvider 1.5.6
• Mikodev.Binary.FSharp 5.8.1
• Akka.FSharp 1.5.41
• Akka.Persistence.FSharp 1.5.41
• Fable.Elmish.Debugger 4.2.1
• HughPH.Box2D 2025.5.10.755
• Ecng.Compilation.FSharp 1.0.52

🚀 Fable 5.0.0-alpha.13 is out!This release fixes several Python-related bugs and lays the groundwork for smoother integration with JavaScript front end frameworks.#fsharp #fablecompiler

— Maxime (@mangelmaxime.bsky.social) 2025-05-04T12:45:44.707Z

That’s all for now. Have a great week.

If you want to help keep F# Weekly going, click here to jazz me with Coffee!