Duolingo is one of the most popular online tools for learning languages, with more than 100 million users. If current trends continue, it will eventually be the most popular. And now, it can also be used for learning Esperanto.

Why is it so popular? First, unlike other systems such as Rosetta Stone, it is completely free. Second, it is effective. According to a study by researchers at the City University of New York and the University of South Carolina, 34 hours of duolingo is equivalent to a semester in a university course. And Duolingo claims to have more users from the United States than there are language students in the country’s public school system. But the ambition of its creators (award-winning Guatemalan computer scientist Luis von Ahn and his former student Severin Hacker) goes even further. They dream of translating the World Wide Web into every human language. In order to do so, they aim to teach all languages through their website.

The Esperanto course. Since the end of May 2015 a beta version of the Esperanto course has been open to everyone. In just the first two weeks, the number of users soared to 25,000, even more than for courses for more traditional languages like Ukranian. Chuck Smith, team leader of the Esperanto course, calculates that 200,000 people could be learning Esperanto through Duolingo by the end of 2015. The quality and content of the course improves and expands every day, thanks in part to user comments. So far the course is available only for English speakers. Once it has undergone sufficient testing, new Esperanto courses might be added to allow students to learn Esperanto from other languages, such as Spanish or Chinese.

Challenges for the future. Having Esperanto as part of Duolingo could mark a turning point for the Esperanto movement. We can imagine a near future where the number of Esperanto speakers could be higher than ever. And growing. We can even foresee a world in which people could learn other languages more easily by way of Esperanto. If so, Esperanto would no longer be a minority language and we need to be prepared for the exciting challenges ahead.