lernu!

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.

The site's content includes various tools for learning Esperanto, such as exercises, games, dictionaries, grammatical overviews, an examination system and a multimedia library with books, music, voice-narrated stories and videos. The site also provides communication services such as an instant messenger, discussion forums on various topics, and news about Esperanto events. Esperantists and Esperanto organizations can advertise their activities and services on the website.