pfSense - pfSense is a free and open source firewall and router that also features unified threat management, load balancing, multi WAN, and more
Charles Proxy - HTTP proxy / HTTP monitor / Reverse Proxy
Zentyal - Linux directory, domain, mail, gateway and infrastructure server for SMBs.
Wireshark - Wireshark is a network protocol analyzer for Unix and Windows. It lets you capture and interactively browse the traffic running on a computer network.
NethServer - NethServer is an operating system for Linux enthusiasts, designed for small offices and medium...
Postman - The Collaboration Platform for API Development