Welcome to F# Weekly,

A roundup of F# content from this past week:

Microsoft News

• .NET Framework 3.5 Moves to Standalone Deployment in new versions of Windows – .NET Blog
• Build AI Agents with Claude Agent SDK and Microsoft Agent Framework | Semantic Kernel
• Building an AI Skills Executor in .NET with Azure OpenAI
• Securing Aspire Apps with Microsoft Entra ID | Aspire Blog
• Roadmap for AI in Visual Studio (February) – Visual Studio Blog
• Performance improvements to MEF-based editor productivity extensions – Visual Studio Blog
• VSCode – January 2026 (version 1.109)

Videos

• .NET Conf Recap: Top announcement and features – YouTube
• Beyond the Prompt: Designing Stateful AI Experiences in .NET – YouTube
• Upgrade to modern .NET with GitHub Copilot: Assess → Plan → Execute – YouTube
• .NET MAUI Community Standup: Live from MAUI Day London – YouTube
• Build AI‑Powered .NET Apps with Telerik – YouTube

Blogs

• An ode to “Slowly” handcrafted code – Urs Enzler
• Intelligent Systems At Cloud’s Edge | SpeakEZ Technologies
• Getting Inline | SpeakEZ Technologies
• Managed Mutability | SpeakEZ Technologies
• Leaning Into LARP Agency | SpeakEZ Technologies
• The Missing Programming Language – Why There’s No S-Tier Language (Yet)

An ode to "slowly" handcrafted codewww.planetgeek.ch/2026/02/02/a… When I open my social media feeds, it's obvious: the age of writing code with our fingers is ending. LLMs can write code much faster.But was it ever about the speed of code creation? I think not.#LLMs #agents #fsharp

— Urs Enzler (@ursenzler.bsky.social) 2026-02-03T09:20:01.010Z

Highlighted projects

• sydsutton/FS.FluentUI: V9 of Microsoft’s FluentUI library, built for F# in the style of Feliz.
• MagnusOpera/FScript: Functional language interpreter – F#/ML inspired
• Lanayx/PipedAgents: F# library for building agents
• afxres/binary: Serialization library for C# and F#.
• dburriss/fsagent: A small DSL and library for generating custom agent files for popular agent tools

New Releases

• FS.FluentUI 3.0.1
• SqlHydra v3.3 + v3
• CCFSharpUtils 0.1.30
• Frank.Analyzers 7.0.0
• Mikodev.Binary.FSharp 5.10.1
• FsAgent 0.3.1
• Equinox.Tool 4.1.2
• FSharp.Data.GraphQL.Server 3.1.0
• DuckDB.FSharp 0.1.6
• Json.Ok 0.0.7
• Facil 2.15.2
• Partas.GitNet 3.0.0
• SwaggerProvider 3.0.0-beta05
• SqlHydra.Cli 4.0.0-alpha.1
• SqlHydra.Query 4.0.0-alpha.1
• Fable 5.0.0-alpha.23

I did a new thing with #fsharp on backend and pinch of #typescript on frontend. It's called Triple19, running on http://www.triple19.com and it's all about my new-ish hobby – Darts. It's quite complex and I'll do tech talk about it one day, but now if you would give it a shot, would ya? #darts

— Roman Provazník (@dzoukr.cz) 2026-02-02T15:18:23.271Z

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!

Claude: Speed up responses with fast mode

New "research preview" from Anthropic today: you can now access a faster version of their frontier model Claude Opus 4.6 by typing /fast in Claude Code... but at a cost that's 6x the normal price.

Opus is usually $5/million input and $25/million output. The new fast mode is $30/million input and $150/million output!

There's a 50% discount until the end of February 16th, so only a 3x multiple (!) before then.

How much faster is it? The linked documentation doesn't say, but on Twitter Claude say:

Our teams have been building with a 2.5x-faster version of Claude Opus 4.6.

We’re now making it available as an early experiment via Claude Code and our API.

Claude Opus 4.5 had a context limit of 200,000 tokens. 4.6 has an option to increase that to 1,000,000 at 2x the input price ($10/m) and 1.5x the output price ($37.50/m) once your input exceeds 200,000 tokens. These multiples hold for fast mode too, so after Feb 16th you'll be able to pay a hefty $60/m input and $225/m output for Anthropic's fastest best model.

Tags: ai, generative-ai, llms, anthropic, claude, llm-pricing, claude-code

2026-02-07

• Add support for Claude Opus 4.6 Fast (Preview)
• Markdown formatting displays in non-interactive mode output
• Display warning when user has no Copilot subscription
• Commands from plugins are now translated into skills
• Add /changelog command to view release notes
• plugin marketplace add accepts URLs as sources
• --no-experimental flag disables experimental features
• CLI interface renders without extra blank line
• /mcp show displays enabled/disabled status for MCP tools
• MCP tool responses now include structured content (images, resources) for richer UI display in VS Code

After Paint 3D, you won’t be able to install 3D Viewer on Windows 11, as Microsoft wraps up the last bits of the “Windows 10 Creators Update.”

In an update to its support document, Microsoft confirmed that it’s removing 3D Viewer from the Windows Store. This means you won’t be able to download or install 3D Viewer anymore, but it’ll continue to work if it’s already installed, at least for a little while.

“3D Viewer is deprecated and will be removed from the Microsoft Store on July 1, 2026,” Microsoft confirmed.

The company recommends using third-party 3D software for viewing 3D art created on Windows. But can you keep using 3D Viewer?

In our tests, Windows Latest observed that 3D Viewer still works on Windows 11, but it’s likely that a future server-side update will soon break the app for everyone. For example, after Microsoft announced that it’s retiring Windows Maps, an update later broke the app, and pushed users to Bing.com

Not the first time Microsoft killed products it once hyped

Before Copilot, there were a bunch of “obsession eras” for Windows, and one of those eras was the “3D era,” where Microsoft pitched Windows 10 as an OS for creators or artists. In fact, Windows 10 received two big updates called “Creators” and “Fall Creators” Update, but as always, Microsoft suddenly decided to give up on its two-year-long efforts.

As part of the Windows Creators Update, Windows shipped with Paint 3D, 3D Viewer, Remix3D, and a bunch of “3D” features. Microsoft also added 3D objects to File Explorer and bet big on Windows Mixed Reality efforts. Unlike Copilot, Paint 3D was well-made, and it actually had a purpose.

However, the approach backfired after Microsoft tried to force people to adapt to the change, which is also exactly what Microsoft is doing with Copilot. Not everybody is a creator, especially a 3D creator, but Microsoft still felt it was the right decision to replace MS Paint with Paint 3D. The plans were later dropped after social media outcry.

Fast forward to 2024, Microsoft confirmed that it’s deleting Paint 3D, which was once supposed to replace MS Paint.

I am not a 3D artist, and I’m not advocating for bloat in Windows 11, but this approach once again shows that Microsoft has a pattern where it picks its favourite product, tries to bake it into everything, then either dials it back or quits after some years or even months.

Microsoft is also deprecating legacy printer drivers

In addition to 3D Viewer, Microsoft confirmed that it’s deprecating legacy printer drivers, which won’t affect most consumers, but it’s still worth noting.

In an updated roadmap, Microsoft says Windows 11 no longer supports V3 and V4 printer drivers if you installed the January 2026 optional (KB5074105). This means older printers that still use the V3 or V4 driver won’t connect or work after the update. In that case, you’ll need to upgrade your printer (buy new hardware) or ask the OEM for help.

Over the past few years, Microsoft dropped support for several Windows apps or features, including WordPad, Legacy DRM services, Suggested Actions, and Cortana, among others.

The post Windows 11: After Paint 3D, Microsoft is removing 3D Viewer, as the “Creators Update” era fades away appeared first on Windows Latest

An anonymous reader shares a report: Republicans' tax cuts shaved billions off Amazon's tax bill, new government filings show. The company says it ran a $1.2 billion tax bill last year, down from $9 billion the previous year, and even as its profits jumped by 45% to nearly $90 billion. That's largely because of the generous new depreciation breaks GOP lawmakers included in their One Big Beautiful Bill, something that's particularly important to Amazon which -- in addition to maintaining a vast infrastructure for its ubiquitous delivery business -- has been spending billions to build out artificial intelligence data centers. Also helping, though less important: The law's expanded breaks for businesses research and development expenses. The company has long been criticized by Democrats for paying little in tax, and it appeared to be bracing for criticism in the wake of the report to the Securities and Exchange Commission.

Read more of this story at Slashdot.

Google shares an update on its work and suggestions for how policymakers can help everyone be more secure in the Quantum Era.