Duolingo: lerni lingvon tradukante la interreton!

https://www.youtube.com/watch?v=WyzJ2Qq9Abs

Duolingo: lerni lingvon tradukante la interreton.
http://duolingo.com/
http://www.fastcoexist.com/1678985/how-the-creator-of-captcha-will-translate-the-entire-internet
http://www.ted.com/talks/luis_von_ahn_massive_scale_online_collaboration.html