After two days with Claude Fable 5 the best way I can describe it is "relentlessly proactive" - here's an example where I dropped in a screenshot of a bug and it span up custom CORS Python servers and used pyobjc-framework-Quartz to capture screenshots simonwillison.net/2026/J…
Who's Who of AI
Simon Willison
Independent AI researcher, creator of Datasette and LLM
Independent AI researcher, creator of datasette.io and llm.datasette.io, building open source tools for data journalism, writing about a lot of stuff at https://simonwillison.net/
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Claude Fable is relentlessly proactive simonwillison.net
I think Anthropic and OpenAI have found product-market fit simonwillison.net
wsj.com
Initial impressions of Claude Fable 5 simonwillison.net
Notes on Pope Leo XIV’s encyclical on AI simonwillison.net
Uber Caps Usage of AI Tools Like Claude Code to Manage Costs simonwillison.net
Gemini 3.5 Flash: more expensive, but Google plan to use it for everything simonwillison.net
Running Python code in a sandbox with MicroPython and WASM simonwillison.net
Publishing WASM wheels to PyPI for use with Pyodide simonwillison.net
Claude Opus 4.8: “a modest but tangible improvement” simonwillison.net
Google I/O, Gemini Spark, Antigravity simonwillison.net
Building Pi With Pi lucumr.pocoo.org
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Articles & links
Given the recent burst of activity around enterprise pricing and contracts, I think April 2026 was the month when both OpenAI and Anthropic found product-market fit simonwillison.net/2026/May/27/...
Supposedly Anthropic are set to have their first profitable quarter. WSJ this time: www.wsj.com/tech/ai/mind...
AI Weekly's analysis
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- Anthropic projects $10.9B in Q2 2026 revenue, more than doubling Q1's $4.8B in a single quarter.
- Claude Code surpassed $1B in annualized revenue within six months of its launch, driven by enterprise developers.
- An expected $559M operating profit marks the first quarter Anthropic covers costs without relying solely on outside capital.
Read full analysis →
Wrote up my initial impressions of Claude Fable 5 - it has a big model smell: slow, expensive and capable of crunching through pretty much everything I threw at it simonwillison.net/2026/Jun/9/c...
When I woke up this morning I didn't think I'd be spending a bunch of time today getting familiar with Catholic theology, but here we are. Notes on Pope Leo XIV's encyclical on AI. simonwillison.net/2026/May/25/...
Uber reportedly now caps coding agents at $1,500/month per employee per tool - seems sensible to me, but it's also an interesting hint at the value Uber thinks these tools are providing simonwillison.net/2026/Jun/3/u...
My notes on Gemini 3.5 Flash - 3x the price of Gemini 3 Flash but Google are planning to use it for many of their own products simonwillison.net/2026/May/19/...
I may have finally found the Python-in-a-sandbox solution I've been looking for... here's my latest experiment, this time running MicroPython in WebAssembly inside my Python applications simonwillison.net/2026/Jun/6/m...
It's now possible to compile Python extensions (C, C++, Rust etc) to WebAssembly and distribute them through PyPI such that Pyodide can install them directly simonwillison.net/2026/Jun/13/...
Notes on Claude Opus 4.8, which Anthropic call "a modest but tangible improvement" - plus pelicans riding bicycles for each of the five different thinking efforts simonwillison.net/2026/May/28/...
I don't have much to say about this year's Google I/O because I prefer to write about products that have shipped, not just "coming soon" announcements - but here are some notes on Gemini Spark and Antigravity simonwillison.net/2026/May/20/...
Simon Willison reposted
Has been a while since I wrote about agentic engineering, so this time around some learnings of maintaining Pi as a junior maintainer to @mariozechner.at lucumr.pocoo.org/2026/5/24/pi...
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Hacker News has an alarmingly high tolerance for slop content these days It also has social norms against accusing something of being written with AI, which means the community has trouble strengthening its immune system against that slop
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