Central Intelligence Agency World Factbook & CIA Factbook entries as JSON files

Common crawl: data scraped from the web for anyone to use

Coroners’ Inquests in 18th century London

Crowd disasters

Etymology database

Foreign Ministers in 13 powerful countries since 1789

Historical datasets

Historical Britain, 1800+

Nobel laureates

Nobel prize

Slave trade (historical)

Small datasets of historical interest for statistics development

UFO reporting (UK)

UFO reporting center (US)

UFO sightings data — National UFO Reporting Center (US)