Collections

Each collection contains a curated set of related concepts waiting to be found. They help you organize your exploration, give you goals to work towards. Examples include Colors, Fruits, Animals, Planets, and many, many more.

Every collection has its own leaderboard. Boards are ranked by how many concepts they've discovered in a collection, with ties broken by the lowest total complexity. Completing one is a goal in itself.

Collections are open source. Have an idea for a new collection? Is there something incorrect or missing? Propose or submit a change on the Collections GitHub repository, your suggestion could end up here for everyone to discover.
Note that collections are a very curated set of concepts, so read the guidelines carefully!