Duolingo is a free language-learning website and crowdsourced text translation platform. The service is designed so that, as users progress through the lessons, they simultaneously help to translate websites and other documents. As of December 2012, the site offers Spanish, French, German, Portuguese (Brazilian), and Italian courses for English speakers, as well as English (American) for Spanish, Portuguese, and Italian speakers. They plan to offer Chinese. Duolingo started its private beta on 30 November 2011, and accumulated a waiting list of more than 300,000 users. Duolingo launched for the general public on 19 June 2012 and as of May 2013 has 3 million users, who use it on average for 30 minutes daily.
The project was started in Pittsburgh by Carnegie Mellon University professor Luis von Ahn (creator of reCAPTCHA) and his graduate student Severin Hacker, and then developed also with Antonio Navas, Vicki Cheung, Marcel Uekermann, Brendan Meeder, Hector Villafuerte, and Jose Fuentes. The project was originally sponsored by Luis von Ahn's MacArthur fellowship and a National Science Foundation grant and is mainly written in the programming language Python. Additional funding was later received in the form of an investment from Union Square Ventures and actor Ashton Kutcher's firm A-Grade Investments.
As of May 2013, Duolingo has 27 staff members and operates from an office in the Pittsburgh neighborhood of Oakland adjacent to Carnegie Mellon's campus.
Portuguese was added to the site for English speakers on 30 October 2012. Italian was added for English speakers on 18 December 2012.
On 13 November 2012 they released their iOS app through the iTunes App Store. The app can be downloaded for free and is compatible with most iPhone, iPod, and iPad devices.
On 14 May 2013, Duolingo announced that their Android app would be available on 29 May 2013.
Θα δοκιμάσω να ξαναθυμηθώ τα γαλλικά μου μέσω των αγγλικών και θα βάλω την μαμά μου να μάθει περισσότερα αγγλικά μέσω των γαλλικών - για να δούμε..