The concern for security has really escalated during the last few years, especially in terms of protecting your computer from undesired, invisible attacks via the Internet. Most of the rise in concern is due to the increasing popularity — and availability — of "always on" Internet connections such as cable modems and DSL lines.
ZoneAlarm is a new network security tool that incorporates a built-in Firewall, Application Control, an Internet Lock, Security Levels, and Zones for the ultimate in comprehensive protection. And unlike its closest competitor BlackICE Defender, ZoneAlarm is freely available for download. Additionally, the client is available in a freeware edition for personal/non-profit use, and commercial users can download a 60-day free evaluation license of the Pro edition.