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

What happens if AI labs train for pelicans riding bicycles? - 13th November 2025
Reverse engineering Codex CLI to get GPT-5-Codex-Mini to draw me a pelican - 9th November 2025
Video + notes on upgrading a Datasette plugin for the latest 1.0 alpha, with help from uv and OpenAI Codex CLI - 6th November 2025

catography 1 chloropleths 1 google 387 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