Ossec - OSSEC is an Open Source Host-based Intrusion Detection System.
Nessus - Nessus Professional is a security platform designed for businesses who want to protect the security of themselves, their clients, and their customers.
Tripwire - Open Source Tripwire software is a security and data integrity tool useful for monitoring and...
AlienVault USM (from AT&T Cybersecurity) - AlienVault USM Anywhere delivers powerful threat detection, incident response, and compliance management for cloud, on-premises, and hybrid environments.
Samhain - The Samhain host-based intrusion detection system (HIDS) provides file integrity checking and log...
Tenable.io - Tenable.io Cyber Exposure platform helps to protect any asset on any computing platform and eliminate blind spots.