• • Ben Maurer • Colin McMillen • Harshad Bhujbal • Initial release May 27, 2007; 10 years ago ( 2007-05-27) Development status Active Classic version: New version: Website reCAPTCHA is a -like system designed to establish that a computer user is human (normally in order to protect websites from ) and, at the same time, assist in the of books. ReCAPTCHA was originally developed by, Ben Maurer, Colin McMillen, David Abraham and at main campus. It was acquired by in September 2009.

Download Software Guitar Pro 5 55294 Tablatures. ReCAPTCHA has completed digitizing the archives of and books from, as of 2011. The archive can be searched from the New York Times Article Archive, where more than 13 million articles in total have been archived, dating from 1851 to the present day. Through, reCAPTCHA was helping to digitize books that are too illegible to be scanned by computers, as well as translate books to different languages, as of 2015. The system has been reported as displaying over 100 million CAPTCHAs every day, on sites such as,,,,,, (since June 2008), and the U.S. 's coupon program website (as part of the ). ReCAPTCHA's slogan was 'Stop Spam, Read Books. Gta San Andreas Pc Brasil Rar Tpb. ' , until the introduction of a new version of the reCAPTCHA plugin in 2014 which is now changed to 'Tough on Bots, Easy on Humans.'

; the slogan has now disappeared from the website and from the classic version of the reCAPTCHA plugin. Manual De Caldera Junkers Eurosmart. A new system featuring image verification was also introduced. In this system, users are asked to just click on a checkbox (the system will verify whether the user is a human or not, for example, with some clues such as already-known cookies or mouse movements within the ReCAPTCHA frame) or, if it fails, select one or more images from a selection of nine images.

An example of how a reCAPTCHA challenge looked in 2007, containing the words 'following finding'. The waviness and horizontal stroke were added to increase the difficulty of breaking the CAPTCHA with a computer program. Scanned text is subjected to analysis by two different programs – one of them, as mentioned the project developer Ben Maurer, is FineReader. Their respective outputs are then aligned with each other by standard string-matching algorithms and compared both to each other and to an English dictionary. Any word that is deciphered differently by both OCR programs or that is not in the English dictionary is marked as 'suspicious' and converted into a CAPTCHA. The suspicious word is displayed, out of context, sometimes along with a control word already known. If the human types the control word correctly, then the response to the questionable word is accepted as probably valid.