Comodo Firewall!

GlassWire is a free network security monitoring tool and analyzer that visualizes your network activity on an easy to use graph, alerts you of possible threats, manages your firewall, and more.

TinyWall is a free software to harden and control the advanced firewall built into Windows Vista, Windows 7 and Windows 8. TinyWall includes a combination of features that sets it apart from both commercial and freeware firewalls: TinyWall does not annoy you with popups at all, yet it is still extremely easy to add exceptions to your firewall rules; TinyWall does not require you to know about ports, protocols and application details; TinyWall prevents malicious programs from modifying the settings of Windows Firewall. »

Gufw is an easy, intuitive way to manage your Linux firewall. It supports common tasks such as allowing or blocking pre-configured, common p2p, or individual ports port(s), and many others! Gufw is powered by Uncomplicated Firewall (ufw).

This personal firewall and intrusion detection application provides comprehensive online security. It constantly monitors your PC for intrusion and reports any findings, so you can take the appropriate action.

Protects your applications from undesirable network incoming and outgoing activity, controls applications internet access. Allows you to control personal information leakage via controlling application network traffic.

Windows Firewall Notifier (WFN) extends the default Windows embedded firewall behavior, allowing to visualize and handle incoming or outgoing connections.

ZoneAlarm Free Firewall blocks hackers from infiltrating your home PC by hiding your computer from unsolicited network traffic. By detecting and preventing intrusions, ZoneAlarm Free Firewall keeps your PC free from viruses that slow down performance, and spyware that steals your personal information, passwords, and financial data.

Radio Silence lets you block individual apps from accessing the internet. It never throws pop-ups on the screen, and is completely invisible.

PC Tools Firewall Plus is a powerful free personal firewall for Windows® that protects your computer by preventing unauthorized users from gaining access to your computer through the Internet or a network. By monitoring applications that connect to the network Firewall Plus can stop Trojans, backdoors, keyloggers and other malware from damaging your computer and stealing your private information.

Hands Off! is an application to monitor and control the access of applications to your network and disks. Being able to monitor the normally unnoticeable activities enables you to make informed decisions regarding the transfer of your private information, hence avoiding confidential information leakage.

Filseclab Personal Firewall Professional Edition is one of the most important software of Filseclab, it is very easy to use and also very powerful. It can provide more secure protection for your PC, and it is FREE.

IceFloor is the first OS X free graphic frontend for PF. Configure the PF firewall in a few clicks using a very simple interface and a step by step in-app configuration guide (Quick Start).

Firestarter is an Open Source visual firewall program. The software aims to combine ease of use with powerful features, therefore serving both Linux desktop users and system administrators.

VoodooShield uses a proprietary proactive whitelist snapshot approach to virus and malware protection. VoodooShield is a patented toggling Desktop Shield Gadget / Computer Lock that automatically toggles to ON and locks your computer when you start a web app. There is never a good reason to let new, non-whitelisted executable code run while a web app is running.