Simon Willison’s Weblog

Introducing the PyPy 1.2 release. It’s been a long time coming, but 1.2 is the first PyPy release to ship with a Just-in-Time compiler! Performance looks pretty impressive.

Posted 12th March 2010 at 11:54 pm

Recent articles

Tips on prompting ChatGPT for UK technology secretary Peter Kyle - 3rd June 2025
How often do LLMs snitch? Recreating Theo's SnitchBench with LLM - 31st May 2025
Talking AI and jobs with Natasha Zouves for News Nation - 30th May 2025

pypy 9 python 1155 performance 89 jit 7

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