Simon Willison’s Weblog

Opera and the Acid3 Test. Screenshot shows 100/100 (live code or it didn’t happen!)—Opera’s codebase must be in extremely good shape to fix so many issues so quickly.

Posted 26th March 2008 at 10:47 pm

Recent articles

Large Language Models can run tools in your terminal with LLM 0.26 - 27th May 2025
Highlights from the Claude 4 system prompt - 25th May 2025
Live blog: Claude 4 launch at Code with Claude - 22nd May 2025

opera 31 browsers 83 acid3 5 web-standards 45

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