Firewall Builder - Firewall Builder is Open Source multi-platform firewall management software that supports Linux...
Charles Proxy - HTTP proxy / HTTP monitor / Reverse Proxy
Shorewall - The Shoreline Firewall, more commonly known as “Shorewall”, is high-level tool for configuring...
HTTP Toolkit - Beautiful, cross-platform & open-source tools to debug, test & build with HTTP(S). One-click setup for browsers, servers, Android, CLI tools, scripts and more.
ufw - Ufw stands for Uncomplicated Firewall, and is program for managing a netfilter firewall.
Weer - A HTTP protocol debugger with Chrome DevTools frontend interface