Claude 4.5 Opus’ Soul Document(lesswrong.com)

290 points by the-needful 10 months ago | 172 comments

The ChatGPT/Codex app bundles a full copy of LibreOffice(simonwillison.net)

441 points by timpera 1 month ago | 206 comments

Short blog note by Simon Willison finding that the ChatGPT/Codex desktop app ships a 1.7GB runtime with Python, Node.js, Poppler, git and LibreOffice for skills.

Changes in the system prompt between Claude Opus 4.6 and 4.7(simonwillison.net)

337 points by pretext 6 months ago | 186 comments

Simon Willison's blog post comparing Anthropic's published Claude system prompts for Opus 4.6 and Opus 4.7, using a git diff to highlight the changes.

Claude's new system prompt doesn't want to reproduce song lyrics(simonwillison.net)

52 points by Bluestein 1 month ago | 37 comments

Anthropic's Project Glasswing sounds necessary to me(simonwillison.net)

11 points by simonw 6 months ago | 2 comments

Serving 200M requests per day with a CGI-bin(simonwillison.net)

298 points by mustache_kimono 1 year ago | 267 comments

Changes in the system prompt between Claude Opus 4.6 and 4.7(simonwillison.net)

337 points by pretext 6 months ago | 186 comments

Simon Willison's blog post comparing Anthropic's published Claude system prompts for Opus 4.6 and Opus 4.7, using a git diff to highlight the changes.

System Card: Claude Mythos Preview [pdf](www-cdn.anthropic.com)

811 points by be7a 6 months ago | 610 comments

Anthropic's PDF system card for the Claude Mythos Preview model, documenting its capabilities, evaluations, and safety assessments.

GPT-5: Key characteristics, pricing and system card(simonwillison.net)

609 points by Philpax 1 year ago | 270 comments

Simon Willison's blog post covering GPT-5's key characteristics, its place in the OpenAI model family, pricing, and notes from the system card.

Claude Sonnet 4.6(anthropic.com)

1268 points by adocomplete 8 months ago | 1129 comments

Anthropic's announcement page for the Claude Sonnet 4.6 model, with a linked system card and launch video.

Unix philosophy and filesystem access makes Claude Code amazing(alephic.com)

377 points by noahbrier 1 year ago | 197 comments

Blog post by Noah Brier on Alephic describing how Claude Code, combined with Obsidian's plain Markdown files and filesystem access, became his agentic operating system.

Claude Opus 4.6(anthropic.com)

2277 points by HellsMaddy 8 months ago | 982 comments

Anthropic's announcement post introducing Claude Opus 4.6, a new version of its flagship AI model, dated February 5, 2026.