Luis von Ahn (born 19 August 1978) is a Guatemalan-American entrepreneur and a Consulting Professor in the Computer Science Department at Carnegie Mellon University in Pittsburgh, Pennsylvania. 

He is known as one of the pioneers of crowdsourcing. He is the founder of the company reCAPTCHA, which was sold to Google in 2009, and the co-founder and CEO of Duolingo, the world's most popular language-learning platform. 

Luis von Ahn was born in and grew up in Guatemala City. Von Ahn grew up in an upper-middle class household with both of his parents working as physicians. He attended a private English language school in Guatemala City, an experience he cites as a great privilege.

When von Ahn was eight years old, his mother bought him a Commodore 64 computer, beginning his fascination with technology and computer science. 

In 2000, he did early pioneering work with Manuel Blum on CAPTCHAs, computer-generated tests that humans are routinely able to pass but that computers have not yet mastered. These devices are used by web sites to prevent automated programs, or bots, from perpetrating large-scale abuse, such as automatically registering for large numbers of accounts or purchasing huge numbers of tickets for resale by scalpers.

In 2007, von Ahn invented reCAPTCHA, a new form of CAPTCHA that also helps digitize books. In reCAPTCHA, the images of words displayed to the user come directly from old books that are being digitized; they are words that optical character recognition could not identify and are sent to people throughout the web to be identified. ReCAPTCHA is currently in use by over 100,000 web sites and is transcribing over 40 million words per day.

According to en.wikipedia