Tenable.io - Tenable.io Cyber Exposure platform helps to protect any asset on any computing platform and eliminate blind spots.
NIXStats - SaaS monitoring tool for window/linux servers and websites. Think up-time robot but with more features.
Qualys - Qualys helps your business automate the full spectrum of auditing, compliance and protection of your IT systems and web applications.
SolarWinds System Management - Performance monitoring and management for applications, Websites, servers, storage arrays and virtual infrastructure.
BreachLock - BreachLock is a versatile platform that provides scalable and smooth penetration testing services for vulnerabilities.
Nodeping - NodePing Server Monitoring and Web Site Monitoring. Simple but powerful Internet service monitoring.