hCaptcha - Do you use a captcha to keep out bots? hCaptcha is a drop-in replacement for reCAPTCHA that earns website owners money and helps companies get their data labeled.
HackerOne - HackerOne provides a platform designed to streamline vulnerability coordination and bug bounty program by enlisting hackers.
MTcaptcha - Enterprise Captcha solutions
Intruder - Intruder is a security monitoring platform for internet-facing systems.
GeeTest CAPTCHA - GeeTest protects your websites, mobile Apps and APIs from bot threats.
Nessus - Nessus Professional is a security platform designed for businesses who want to protect the security of themselves, their clients, and their customers.