reCAPTCHA

I recently found out about this project during one of my tutorials, and I am certainly impressed by the efforts of Carnegie Mellon University.

What are CAPTCHAs?

The term CAPTCHA is short for "Completely Automated Public Turing test to tell Computers and Humans Apart". It is a type of challenge-response test used in computing to ensure that the response is not generated from a computer. We commonly see this test being used in systems that are vulnerable to spam (e.g. Hotmail, Yahoo!, Paypal).


What is reCAPTCHA?

A free CAPTCHA service that helps to digitize books, newspapers and old time radio shows. The book pages are being photographically scanned, and then transformed into text using "Optical Character Recognition" (OCR). The transformation, however, is not perfect. Words that cannot be recognized will be sent for human readers to decipher through CAPTCHA. In a nutshell, reCAPTCHA is digitizing books one word at a time.

To find out more about this amazing project and what you can do to help, visit reCAPTCHA at http://recaptcha.net/