Real research projects that need human eyes: classify galaxies, transcribe ship logs, count penguins. Ten minutes of your attention becomes a line in someone’s paper.
Photograph anything alive and a mix of naturalists and machine vision will tell you what it is. Verified sightings become open biodiversity records scientists actually use.
Long-run data on health, energy, food and poverty, charted and sourced, with the underlying numbers downloadable. The place to check a claim about how the world is going.
The improbable success story of the internet. Start anywhere; you will be somewhere else in an hour.
Draw a fish and release it into a shared tank where everyone else's fish are already swimming. Vote for your favourites.
Thousands of jigsaw puzzles uploaded by the community, from a dozen pieces to a few thousand, playable in the browser.
Step-by-step photo guides for making almost anything, from furniture to robots to cakes, written by the people who made them.
