pfSense - pfSense is a free and open source firewall and router that also features unified threat management, load balancing, multi WAN, and more
NetWrix Auditor - Configuration Auditing of IT Infrastructure
OPNsense - OPNsense® you next open source firewall. Free Download. High-end Security Made Easy™. Offers Intrusion Prevention, Captive Portal, Traffic Shaping and more.
ManageEngine ADAudit - ManageEngine ADAudit is a real-time windows active directory auditing tool.
IPFire - IPFire is a server distribution with intended to use as a firewall.
PingCastle - Because the Active Directory security lies in the process and not in expensive tools, our solution is simple: download PingCastle and apply its methodology.