Language-learning websites

lernu! is a multilingual, web-based free project for promoting and teaching Esperanto. The name Lernu comes from the imperative form of the Esperanto verb lerni, meaning "to learn". The site is run by E@I, an international youth organization, which started as a working group of the World Esperanto Youth Organization.

Memrise is a British language platform that uses spaced repetition of flashcards to increase the rate of learning. It is based in London, UK.

organization which promotes Klingon language (Star Trek)

language exchange app

Lingvist is an adaptive language-learning platform, available in an international public free beta version since 2014.

department of the BBC World Service devoted to English language teaching