This library protects websites from spam and other attacks. It prevents bad bots from delivering their junk, and in many cases, from ever reading your site in the first place. Welcome to a whole new way of keeping your service, forum, wiki or content management system free of spam and other attacks. Gatekeeper is a PHP-based solution for blocking spam and the robots which deliver it. This keeps your site's load down, makes your site logs cleaner, and can help prevent denial of service conditions caused by spammers.