Simon Willison’s Weblog

Cartographer.js. “Thematic mapping for Google Maps”—which means an easy way of adding heat maps (aka chloropleths), pie charts and point clusters as a layer over a Google map.

Posted 1st November 2009 at 1:20 pm

Recent articles

Highlights from my appearance on the Data Renegades podcast with CL Kao and Dori Wilson - 26th November 2025
Claude Opus 4.5, and why evaluating new LLMs is increasingly difficult - 24th November 2025
sqlite-utils 4.0a1 has several (minor) backwards incompatible changes - 24th November 2025

catography 1 chloropleths 1 google 391 google-maps 53 graphs 7 heatmaps 3 infographics 7 mapping 54 maps 43 piecharts 1 visualisation 15

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