Our guestbook is now protected by the ReCaptcha™ Anti-Bot and Spam Filter. ReCaptcha™ is an implementation of the CAPTCHA system which many sites use to prevent automatic spam servers from signing up for the purpose of spamming or flooding a website or blog.

Captcha is a type of challenge-response test used in computing to ensure that the response is not generated by a computer. The process involves one computer (a server) asking a user to complete a simple test which the computer is able to generate and grade. Because other computers are unable to solve the CAPTCHA, any user entering a correct solution is presumed to be human. A common type of CAPTCHA requires that the user type the letters or digits of a distorted image that appears on the screen.

The term "CAPTCHA" was coined in 2000 by Luis von Ahn, Manuel Blum, Nicholas J. Hopper (all of Carnegie Mellon University), and John Langford (then of IBM). It is a contrived acronym for "Completely Automated Public Turing test to tell Computers and Humans Apart", trademarked by Carnegie Mellon University.