Firestarter is an easy-to-use free firewall tool for Linux that has a wizard that allows you to customize your firewall, a real-time firewall monitor that allows you to view intrusion attempts, a graphical interface that works under GNOME and KDE, and support for Linux kernels 2.4 and 2.6. Firestarter is one way to set up your system so that it is protected from intrusions.
Size: 600KB
Look 'n' Stop Lite is a free Windows firewall that filters inbound and outbound traffic from your computer.
*Note that this is a 30 day free trial.
Size: 3.1MB
A Windows 98/ME/NT/2000/XP firewall that has network packet filters, network events filters (that allows you to block application level events) and process activity filters (that hopefully blocks application hijacking attempts where a trojan uses your browser to send information to the internet). Please read here before installing.
A rule-based Windows network firewall that filters IP and non-IP traffic, supports configurations for multiple network adaptors, has a learning mode and comes with a set of predefined rules.
Size: 1MB
Guarddog is a firewall configuration utility for Linux iptables. It also lets you maintain and modify the firewall in place. It uses a "what is not explicitly allowed, is denied" philosophy. The software is released under the GNU GPL.
