Network security is a hot topic these days, and intrusion detection systems are playing a greater role in network security. Refeeq Ur Rehman's book Intrusion Detection with SNORT, Apache, MySQL, PHP, ...

If you don’t have a lot of budget at your disposal, these open-source intrusion detection tools are worth a look.

List of free intrusion detection and prevention software, system & tools for Windows - Snort, OSSEC for Enterprise use and WinPatrol for home use.

Nokia plans to integrate Sourcefire’s intrusion-prevention software into its line of network security appliances by year’s end. Sourcefire, which is based on the open-source Snort software ...