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.
Nmap - Nmap Free Security Scanner, Port Scanner, & Network Exploration Tool. Download open source software for Linux, Windows, UNIX, FreeBSD, etc.
MTcaptcha - Enterprise Captcha solutions
Angry IP Scanner - Open-source and cross-platform network scanner designed to be fast and simple to use
GeeTest CAPTCHA - GeeTest protects your websites, mobile Apps and APIs from bot threats.
Advanced IP Scanner - Advanced IP Scanner shows all network devices, gives you access to shared folders, and can even remotely switch computers off. Download it Free.