Colophon

• Type
  Text is set in Newsreader, by Production Type; labels and interface in IBM Plex Mono, by Mike Abbink and Bold Monday; and a few small things in Silkscreen, by Jason Kottke.
• Built with
  HTML, CSS and JavaScript, coded primarily by Claude Opus 5.5, with no framework. A short Node script pre-renders every page, so the site reads without JavaScript; in the browser, a small client-side router takes over.
• Hosting
  Vercel, with votes, comments and suggestions stored in Upstash Redis.
• Data
  Each problem is a single JSON file in the repository. The combined dataset is at /data/problems.json, and a guide for AI agents is at /llms.txt.
• Source
  github.com/benjaminbreen/open-problems-in-history
• Writing
  Questions chosen by Benjamin Breen; most problem pages researched and drafted with Claude Opus 5.5, then edited and checked by hand. See Methods.
• Lead author
  Benjamin Breen, in 2026.