pfSense - pfSense is a free and open source firewall and router that also features unified threat management, load balancing, multi WAN, and more
ManageEngine ADAudit - ManageEngine ADAudit is a real-time windows active directory auditing tool.
Zentyal - Linux directory, domain, mail, gateway and infrastructure server for SMBs.
Imperva - Imperva data center security provides tools to combat attack, theft, and fraud, mitigate risk, and streamline regulatory compliance.
NethServer - NethServer is an operating system for Linux enthusiasts, designed for small offices and medium...
LepideAuditor - LepideAuditor Suite - A change auditing software for Active Directory, GPO and Exchange Server.