The ChatGPT/Codex app bundles a full copy of LibreOffice

1st September 2026 I was poking around in my ~/.cache/ folder using OmniDiskSweeper when I spotted something interesting. The OpenAI Codex desktop app (since rebranded to just ChatGPT) has 1.7GB of stuff in there in a folder called codex-primary-runtime, including a full Python installation, a full Node.js installation, and native binaries for Poppler, git, and the LibreOffice open source office suite (which forked from OpenOffice.org in 2010): The ~/.cache/codex-runtimes/codex-primary-runtime/plugins/openai-primary-runtime/plugins/documents folder includes skills which tell Codex how to find and use those binaries. Recent articles Understanding ChatGPT Work - 30th August 2026 Conceptual integrity and counting lines of code - 19th August 2026 Qwen 3.8 27B is excellent, but it defaults to wildly overthinking things - 16th August 2026 This is a note by Simon Willison, posted on 1st September 2026. Monthly briefing Sponsor me for $10/month and get a curated email digest of the month's most important LLM developments. Pay me to send you less!