| Deno is joining Cloudflare |
https://deno.com/blog/cloudflare |
The Deno team released the first version of [celld](https://github.com/denoland/celld) back in August - their open source implementation of the Durable Objects pattern from Cloudflare Workers.
Today, Cloudflare are acquiring Deno outright, with the goal of building on `celld` to "make workerd self-hosting a first-class supported way to build and run apps using the Workers programming model" (see [the Cloudflare blog](https://blog.cloudflare.com/deno-joins-cloudflare/).)
The bad news is that Deno itself will not be maintained by Cloudflare beyond the next year:
> We will support the [Deno runtime](https://github.com/denoland/deno) for another year with monthly releases containing bug fixes and security updates. After that year we will end our development of the Deno runtime. Deno will remain open source, and we welcome others who want to continue its development.
Deno (and Node.js) creator Ryan Dahl explained that decision in [a comment](https://news.ycombinator.com/item?id=50019911#50023277) on Hacker News:
> It's a joint decision and I agree with it. I'm most invested in its success and have put the most work into it - and I no longer think it's where I can do the most important work. There are some good ideas in Deno and it's well engineered - but it ultimately is not solving big problems. It has been sucked into the gravity well of node compatibility, which forces it to behave exactly as Node does. Why reimplement Node? It works. Marginal performance or UX or security benefits are not enough.
>
> I'm interested in building powerful new abstractions. celld has been working remarkably well, depending only on object storage for coordination and persistence. It is not just a slightly different API to interact with the file system or network - it's an entirely new model for server development.
My favorite feature of Deno has long been the permissions system, where you can run a Deno script and specify exactly which files and folders it can read and write to, and which network hosts it can access.
Node.js [has a similar permissions model](https://nodejs.org/api/permissions.html) these days, added [in Node v20.0.0](https://nodejs.org/en/blog/release/v20.0.0) in April 2023 and declared stable [in Node v22.13.0](https://nodejs.org/en/blog/release/v22.13.0) in January 2025. They don't yet support allow-listing specific network hosts though - networking is either on or off. |
2026-10-09 22:48:37+00:00 |
| Anti-Patterns in Software Blogging |
https://refactoringenglish.com/blog/anti-patterns-software-blogging/#summary |
Some excellent writing advice from Michael Lynch. Michael warns against "meandering intros", misjudging your reader's existing knowledge, assuming they'll read your previous posts, and excessive formality.
He also warns against [overreliance on links](https://refactoringenglish.com/blog/anti-patterns-software-blogging/#overreliance-on-links) as an excuse not to explain terminology. This one hurt! I do this all the time, but I have a nagging suspicion that almost nobody ever clicks on them.
(In [a Lobste.rs comment](https://lobste.rs/s/rwdufq/anti_patterns_software_blogging#c_qdhhsd) Michael clarifies that "My rule of thumb is that my article should still make sense to the reader even if they don't click any links". That works for me.)
This point about using your own voice is crucial:
> Beginner software bloggers suffer from a mass delusion that you have to write in a stiff, overly formal way for people to take you seriously [...]
>
> Just write the way you talk.
>
> With so many developers delegating their writing to AI, software blogging is becoming bland and homogenous. Readers are hungry for writing with personality. |
2026-10-07 14:53:51+00:00 |
| OpenAI “rogue” agent activities found on Wikimedia projects |
https://wikimediafoundation.org/news/2026/10/05/openai-rogue-agent-activities-found-on-wikimedia-projects/ |
Given how tempting a target wikis are for rogue agent swarms, it's not a huge surprise that Wikipedia found evidence of that activity once they went looking:
> The Wikimedia Foundation conducted its own investigation to see whether Wikimedia websites had been similarly affected by AI agents, focusing on those operated by OpenAI. We can confirm that we have discovered some activity by these “rogue” OpenAI agents on Wikimedia platforms. The unauthorized bot activities included edits to our wikis, some unsuccessful attempts to exploit a public note-taking tool we host, and heavy traffic, which are described more below.
They found evidence of agents editing sandbox pages, trying to use pieces of infrastructure such as Etherpad to help proxy content from elsewhere, and saw widespread crawling and "hundreds of thousands of data queries" to their Wikidata Query Service.
My best guess is that most of this was a similar (or the same) swarm of agents as those that [defaced that German wiki](https://simonwillison.net/2026/Sep/4/rogue-agent-wikis/) while training for research tasks.
The Wikipedia sandbox wiki edits appear to have started on May 12th, and the initial test edits to the UseModWiki Sandbox page reported by that incident started on May 11th. |
2026-10-07 00:16:45+00:00 |
| Introducing Mistral Large 4: Le chonk |
https://mistral.ai/news/mistral-large-4/ |
Mistral are back in the game. Today they're releasing a preview of Mistral Large 4, a 1 trillion parameter, 49 billion active parameter model trained on their own cluster of 3,800 NVIDIA Grace Blackwell GPUs.
The preview is available via their API. They promise to release the open weights model at the "end of this month".
The model only supports two reasoning levels - "none" and "high" - via the Mistral API. Here are [both pelicans](https://tools.simonwillison.net/markdown-svg-renderer?url=https%3A%2F%2Fgist.github.com%2Fsimonw%2F0db8b8196e57711b352f6c5857cf5b35) - the "high" one looks better, though surprisingly it only used 2,717 output tokens compared to "none" which used 3,275:
On Artificial Analysis [it scores 38](https://artificialanalysis.ai/models/mistral-large-4), just behind DeepSeek 4.1 Flash, which is a 552B model. It's a *huge* improvement on last December's Mistral Large 3, which drew [this terrible pelican](https://tools.simonwillison.net/markdown-svg-renderer?url=https%3A%2F%2Fgist.github.com%2Fsimonw%2F0df5e656291d5a7a1bf012fabc9edc3f#response-1) and [scored 9 on AA](https://artificialanalysis.ai/models/mistral-large-3).
It's certainly not a Fable-class model, but it's great to see Mistral put out a model that's back to being maybe about 6 months behind the frontier. |
2026-10-06 20:18:19+00:00 |
| Claude Sonnet 5.5 |
https://www.anthropic.com/claude-sonnet-5-5 |
New Sonnet model from Anthropic today. They say it "runs 30%+ faster, and costs up to 30% less for most work" - it's priced the same as Sonnet 5 but appears to beat it on every benchmark, and should be cheaper to run as well.
[Here are some pelicans riding bicycles](https://tools.simonwillison.net/markdown-svg-renderer?url=https%3A%2F%2Fgist.github.com%2Fsimonw%2F1d85a9be7f3ecce26e7f1569161a0d01). Sonnet 5.5 suffered from [the same bug as Opus 5.5](https://simonwillison.net/2026/Sep/22/opus-and-sol-and-luna/#claude-opus-5-5-max-over-thinks-to-the-point-of-breaking): the "max" thinking effort pelican thought for 128,000 tokens (at a cost of $1.28) before running out of tokens and failing to produce an SVG.
Here's the pelican it gave me for thinking effort "xhigh", at a cost of 5.74 cents and taking 41 seconds:
Sonnet 5.5 appears to be almost as good as Opus 5.5 on some coding tasks, including various [viral 3D animation tricks](https://x.com/claudeai/status/2104674987164782598).
The most interesting thing about Sonnet 5.5 is that it's now the model used for the free tier on [claude.ai](https://claude.ai/). OpenAI's ChatGPT free tier uses Luna 5.6, which means Anthropic currently have a much more capable free offering.
I ran this prompt against that free tier:
> `build me an HTML page that renders a three-dimensional pelican riding a bicycle using WebGL`
And got back [this page](https://static.simonwillison.net/static/2026/claude-sonnet-5.5-free-3d-pelican.html), which is a solid effort.
Anthropic's announcement reiterates that Haiku 5.5 will be available "in the coming weeks". I really hope that one is price-competitive with GPT-6 Luna! |
2026-09-28 22:07:38+00:00 |
| SF October 14th: A Birds of a Feather Session on Agentic Engineering |
https://luma.com/vxuiuyvg |
I'm hosting an evening event with Jesse Vincent in San Francisco on Wednesday 14th October for people who are building weird and interesting things with and on top of coding agents.
Think of it as an agentic show-and-tell:
> Compare notes with other builders and experimenters on things you’re trying, what you're learning, and what you haven’t figured out yet. We’re especially interested in work you haven’t discussed publicly, odd experiments, or unfinished projects that don’t have an obvious market.
>
> Expect one flowing conversation with an informal show-and-tell. Sharing something you’re working on is encouraged but no presentation is required.
This isn't about product pitches, it's about much earlier explorations than that. This agentic AI stuff is weird! Let's celebrate and lean into that weirdness. |
2026-09-23 02:53:19+00:00 |
| Cloudflare Python Workers are now generally available |
https://blog.cloudflare.com/python-workers-ga/ |
After a two year preview, Cloudflare's support for running Python code in their server-side Workers platform is now stable: "Python is now a first-class, fully supported language on the Cloudflare Developer Platform".
A neat thing about this is how it works. Cloudflare are running Python compiled to WebAssembly via Pyodide in their V8-based [workerd](https://github.com/cloudflare/workerd) runtime.
This comes with some limitations, [documented here](https://developers.cloudflare.com/workers/languages/python/stdlib/) - most notably both `multiprocessing` and `threading` are non-functional in the WebAssembly VM.
One particularly interesting detail of this is the local development environment story - their [pywrangler](https://developers.cloudflare.com/workers/languages/python/#the-pywrangler-cli-tool) development tool (confusingly packaged as [workers-py](https://pypi.org/project/workers-py/) on PyPI) runs a full local simulation of their stack, including executing code with Pyodide in WebAssembly in V8 in a 123MB `workerd` binary, which for me ended up in `node_modules/@cloudflare/workerd-darwin-arm64/bin/workerd`.
Python Workers represent a significant investment in the wider Python ecosystem by Cloudflare. The release announcement is credited to Gyeongjae Choi, Dominik Picheta, and Hood Chatham - Gyeongjae and Hood are both Pyodide core maintainers. |
2026-09-21 22:25:44+00:00 |
| Gemini Hacked Three Companies in First Known Breakout by Google’s AI |
https://www.wsj.com/tech/ai/gemini-hacked-three-companies-in-first-known-breakout-by-googles-ai-5c0baba2 |
Gemini finally caught up on [Felony Bench](https://www.felonybench.com/)!
> The hacks, which the company confirmed on Friday, occurred in May as part of a test run by the company Irregular, which was also involved in similar incidents disclosed by OpenAI, Anthropic and Meta.
>
> In one of the cases, the model guessed passwords until it gained access to a protected system. In the other two cases, the model found credentials in a public repository that allowed it to then access protected systems. In each case, the model ended the intrusion after determining it had accessed a real company’s systems, Google said.
Gemini is apparently less determined than other models, and decided *not* to keep going.
Google knew about these in July, but chose not to disclose them until the WSJ reached out, presumably based on a tip.
> Google said it didn’t consider the hacks to warrant public disclosure—because its model didn’t cause harm to the companies and ended each intrusion immediately upon determining it had hacked a real company rather than a simulated one. |
2026-09-18 23:57:57+00:00 |
| The Creative Spirit of Who Framed Roger Rabbit |
https://blog.cypressf.com/post/828067789747208192/the-creative-spirit-of-who-framed-roger-rabbit |
I love [Who Framed Roger Rabbit](https://en.wikipedia.org/wiki/Who_Framed_Roger_Rabbit), the 1988 movie by Robert Zemeckis. I haven't watched it in quite a few years, and Cypress Frankenfeld just pointed out this sequence from early in the movie:
<video
src="https://static.simonwillison.net/static/2026/pelican-bicicle-roger-rabbit.mp4"
poster="https://static.simonwillison.net/static/2026-09-18/IMG_8118.jpeg"
preload="none"
loop controls
playsinline muted
width="886"
height="480"
style="display: block; width: 100%; height: auto;"
></video>
It's a pelican riding a bicycle!
Look closely and you'll note that the pelican is animated while the bicycle is a real bicycle. Apparently they filled the wheels with water to add stability, then set it running and guided it with a cable.
Cypress [gathered more details](https://blog.cypressf.com/post/828067789747208192/the-creative-spirit-of-who-framed-roger-rabbit) on the scene. What a delight. |
2026-09-18 14:36:41+00:00 |
| Be alert: targeted attacks on prominent Rustaceans |
https://blog.rust-lang.org/2026/09/17/targeted-attacks/ |
Important warning from Adam Harvey and the crates security team:
> We believe that there is an ongoing campaign targeting rust-lang members and owners of popular crates that is attempting to compromise devices and accounts in order to use them to publish malware.
>
> A video call is set up for something positive — maybe for a job, maybe for a project, maybe for a contract opportunity — and then that's used as a vector to either get the target to install something on their computer (such as a purportedly missing audio codec) or execute another command (for example, via putting a command on the clipboard).
Last month this trick was used in a successful [supply chain attack against the array ref crate](https://blog.rust-lang.org/2026/08/20/supply-chain-attack-on-arrayref/), among others.
Any piece of software that depends on open source (which is almost *every* piece of software) has a network of human beings who are potential attack vectors - everyone with publishing rights to any of the packages in the dependency network for that software.
I guess our best defense right now is [dependency cooldowns](https://blog.yossarian.net/2025/11/21/We-should-all-be-using-dependency-cooldowns) - giving new package releases a few days before upgrading to them, in the hope that supply chain attacks like this will be spotted by someone else. |
2026-09-17 23:59:19+00:00 |