Simon Willison’s Weblog

Tutorial: Creating a Mozilla Extension (via) I spent nearly an hour looking for this the other day with no success.

Posted 14th July 2004 at 8:17 pm

Recent articles

JustHTML is a fascinating example of vibe engineering in action - 14th December 2025
OpenAI are quietly adopting skills, now available in ChatGPT and Codex CLI - 12th December 2025
GPT-5.2 - 11th December 2025

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