If you want to learn about the concept and armsrace, here is a paper with plenty of resources (this is in a game context, though not website, although there is

If you want to learn about the concept and armsrace, here is a paper with plenty of resources (this is in a game context, though not website, although there is the most advanced detection here): http://iseclab.org/papers/botdetection-article.pdf http://iseclab.org/papers/botdetection-article.pdf Here is an open source system demo'd at BlackHat Europe 2011 (that checks it is a proper browser (with DOM/Javascript/etc), also good against DDoS. https://github.com/yuri-gushin/Roboo https://github.com/yuri-gushin/Roboo Project Honeypot (scans inbound ips) good against spambots: https://www.projecthoneypot.org/ https://www.projecthoneypot.org/ Here are some commercial solutions: CloudFlare's ScrapeShield -https://www.cloudflare.com/apps/scrapeshield https://www.cloudflare.com/apps/scrapeshield Distil Networks - http://www.distilnetworks.com/ http://www.distilnetworks.com/ Scrape Sentry - http://www.scrapesentry.com/ http://www.scrapesentry.com/ Fireblade - http://www.fireblade.com/ http://www.fireblade.com/