Simon Willison’s Weblog

Use HTML 4.01, not XHTML. Why Stuart’s book uses HTML, not XHTML.

Posted 21st February 2005 at 12:52 pm

Recent articles

The Summer of Johann: prompt injections as far as the eye can see - 15th August 2025
Open weight LLMs exhibit inconsistent performance across providers - 15th August 2025
LLM 0.27, the annotated release notes: GPT-5 and improved tool calling - 11th August 2025

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!

Sponsor & subscribe