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- Newsletter 028 - September
Hi, and welcome to the September edition of this newsletter! As always, feel free to reply to this email to get in touch. Or ping me on any of the socials I’m on (see bottom of newsletter for links).
If you get value from this newsletter, please help me out by sharing it on your socials and with your tech friends and colleagues - it really helps me spread the word and keep the newsletter going 🙏 (at-mention me, and I’ll repost).
📰 News items and dev picks
Dotnet news
.NET Aspire 9.5 - Another release of the awesome .NET Aspire! And includes a Gen AI visualiser!
Announcing .NET 10 Release Candidate 1 - “This is our first of two release candidates which come with a go-live support license so you can confidently use this release for your production applications.”
LINQPad 9 AI editing with diff - “New to LINQPad 9: Give AI an instruction or ask a question without leaving the editor. Full red/green diffing via a robust custom engine. Works with a provider of your choice and any model; no subscription required.”
.NET “eventing framework” plan scraped - In this post in the initial GitHub issue, David Fowler says that after reviewing feedback, they’ve decided not to go ahead with it. If you missed the initial discussion, basically they were floating the idea of having an eventing framework as part of dotnet.
New Trusted Publishing enhances security on NuGet.org - And here’s a nice post by Andrew Lock about it.
.NET Foundation elections - meet the candidates - Voting opens on the 1st October.
AI news
GitHub Copilot CLI is now in public preview - “We’re bringing the power of GitHub Copilot coding agent directly to your terminal. With GitHub Copilot CLI, you can work locally and synchronously with an AI agent that understands your code and GitHub context.”
Copilot Spaces is now generally available - “With GitHub Copilot Spaces, you can bring together the context it needs - files, pull requests, issues, and repos - so that Copilot’s responses are always grounded in your project. With spaces, Copilot doesn’t just generate output. Copilot understands your systems, your standards, and your open tasks.”
MCP tool support added to ChatGPT (developer mode) - You can now turn on “developer mode” which allows you to add MCP Servers to ChatGPT. Unfortunately, it does mean your prompt textbox always has a big red box around it, with text “Developer mode”, and also memory is disabled.
The GitHub MCP registry - Search tons of MCP Servers in the new GitHub MCP Registry. You can even install MVP Servers straight to VsCode from it.
AGENTS.md Emerges as Open Standard for AI Coding Agents - this is now becoming a new standard for AI instruction files. So rather than different file names / conventions for Claude Code, OpenAI Codex, VsCode, etc. your codebase can have a single AGENTS.md that they’ll all use.
AGENTS.md support in VsCode - This file gets picked up as well as the
copilot-instructions.mdfile that we’ve been using up until now. This matches the news item above.Notion 3 released (with agents!) - I’m a huge fan of Notion and use it to manage many aspects of my life. They’ve had AI stuff in there for a while (which to be honest, I don’t use) - but with v3, it looks like they’ve taken it to the next level by adding agents to do much more for you. Whilst I don’t really want AI to write my notes for me - I can totally see myself using this for automation workflows.
ChatGPT adds “branched conversations” - “you can now branch conversations in ChatGPT, letting you more easily explore different directions without losing your original thread.”
Others
Project OPULIS - “This book is a collection of stories from the women who helped build Microsoft, from the early days of software to its modern era.”
Google will not be forced to sell Chrome, federal judge rules - In case you missed it, for a while there’s been the possibility that Google would be forced to sell Chrome - with many interested parties - eg. OpenAI, Perplexity, and more. Some bids made were around the $35 billion mark!
.NET Days Online 2025 - Free two-day online event on October 8/9th.
Dev Comic pick of the month
I went to the pub for lunch today with a few colleagues, so this one felt like a good choice! 🙈🍺
(Source)
Dev Tip - GitHub Copilot Agents
This is a fantastic introduction to coding Agents by James Montemagno. Highly recommended.
And following along nicely was this announcement about the GitHub Copilot CLI! (also in the news section above)…
We’re testing something 🧪
GitHub Copilot CLI is now in public preview. Build, debug, and deploy with GitHub Copilot coding agent without leaving your terminal.
Try it out and tell us what you think 👇
— GitHub (@github)
7:28 PM • Sep 25, 2025
Sponsorship opportunities
I’m looking for sponsors for both the podcast and this newsletter. Details of podcast sponsorship can be found here. Feel free to reply to this email to discuss further.
The Podcast 🎙
I’ve recorded two episodes during September - with them both coming out over the next few weeks…
The first was with Olorunfemi Davis, and we chatted about AI, Microsoft's various Copilots (including Copilot Studio), Semantic Kernel, and more!
And the next was with Jan De Dobbeleer, the creator of Oh My Posh, which is what we geeked out on!
I’ve been a long-time user of oh-my-posh, and this is my terminal setup…
What does yours look like? Feel free to reply with screenshots - I love seeing what people have done with their terminals :)
Also, just a reminder that we have a Discord community for the podcast! It would be great to see you there :)
Podcast Discord community
.NET Oxford (user-group)
The next .NET Oxford meetup will be in October, and we’re trying something a bit different this time! We’re going to attempt an “unconference”. No set agenda, no prepared talks, no slides. Instead, the community decides what we talk about. We’ll kick off by gathering ideas from everyone in the room - questions, topics, challenges, or experiences you’d like to share. Then we’ll vote, group them, and dive into the discussions.
My Dometrain Courses
Below are details of my Dometrain courses. There’s also a bundle that includes both the Docker and Kubernetes courses, which can be found here.
Docker for Developers
This course will teach you everything you need to know about Docker and containers. From what containers and images are; to how to build your own; to security and networking; docker-compose; and much more!
Kubernetes for Developers
Once you understand Docker, containers, images, etc - it’s time to move onto the next level and learn a container orchestrator - and Kubernetes has clearly won the battle here! My Kubernetes course is rammed-packed full of demos (pretty much all the way through), which are easy to follow along with downloadable YAML files and scripts. We start with the basics, then later move on to more advanced topics like services meshes and operators.
JetBrains Rider
Rider is an amazing .NET IDE by JetBrains. This course is 6 hours of content - covering hotkeys, refactoring, navigation, debugging, git, testing, AI, profiling, remote collaboration, and much much more!
.NET Aspire
.NET Aspire is Microsoft's vision for how every .NET developer will develop systems. It is a cloud-ready stack for production-ready, distributed applications using .NET, and it makes it extremely easy to develop, run, and test your systems locally. With unmatched dev-time orchestration, integrations with third-party services, and excellent tooling, .NET Aspire aims to make working with the cloud and technologies like Docker and Kubernetes easier than ever.
If you’ve made it this far into the newsletter - I’m hoping that means you’ve
both enjoyed it and found it useful. If you can help me out and share with your developer friends at work and on social media, that would be amazing!
Again - feel totally free to reach out to me, and let me know your thoughts on the newsletter. And see you back in your inbox next month for the next edition! 👋
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