ufw - Ufw stands for Uncomplicated Firewall, and is program for managing a netfilter firewall.
LuLu by Objective-See - LuLu is the free open-source macOS firewall that aims to block unauthorized (outgoing) network...
TinyWall - Lightweight and non-intrusive firewall
Plasma Firewall - Plasma Firewall is an open-source control panel with which you can manage your system firewall.
Gufw - Gufw is an easy, intuitive way to manage your Linux firewall.
ferm - ferm is a tool to maintain complex firewalls, without having the trouble to rewrite the complex...