pfSense - pfSense is a free and open source firewall and router that also features unified threat management, load balancing, multi WAN, and more
Zentyal - Linux directory, domain, mail, gateway and infrastructure server for SMBs.
IPFire - IPFire is a server distribution with intended to use as a firewall.
NethServer - NethServer is an operating system for Linux enthusiasts, designed for small offices and medium...
OPNsense - OPNsense® you next open source firewall. Free Download. High-end Security Made Easy™. Offers Intrusion Prevention, Captive Portal, Traffic Shaping and more.
VyOS - VyOS in an open source Linux-based operating system sold and distributed by Sentrium corporations. It is geared toward IT specialists and network administrators for the purpose of securing network and company data... read more.