XP Protection - Internet Security Software
- Intrusion detection system to make you aware of any attacks from hackers and Trojans [Windows, Shareware].
- http://www.tweakyourwindows.com/Software-Details/34576/XP-Protection.html

LinuxSecurity IDS Resources
- Collection of IDS-related resources made available by the linuxsecurity.com community.
- http://www.linuxsecurity.com/component/option,com_weblinks/catid,117/Itemid,134/

myNetWatchman.com
- Intrusion Reporting and Response. Users forward firewall logs that are aggregated and analysed to identify incidents that are reported to the responsible party.
- http://www.mynetwatchman.com/

Talisker Security Wizardry
- Large index of computer security resources, including a glossary of Intrusion Detection and Prevention systems.
- http://www.securitywizardry.com/

COAST Intrusion Detection Hostlist
- Clearinghouse listing of many of the Internet resources associated with intrusion detection and prevention systems. Includes inventories of commercial products, research projects, and other IDS-centric material.
- http://www.cerias.purdue.edu/about/history/coast_resources/intrusion_detection/

Michael Sobirey's IDS Page
- An excellent index of most currently available IDS and IPS products, including vendor contact information.
- http://www.cse.sc.edu/research/isl/mirrorSobireys.shtml

Internet Storm Center
- Operated by the SANS Institute, the ISC provides a user-supported infrastructure for intrusion detection systems to share information about ongoing attacks that span countries, networks, and administrative boundaries.
- http://isc.incidents.org

Security Resources for Windows Network Administrators
- Provides books, articles, software and other information on penetration testing and other security issues. Geared toward Windows NT/2000/XP Network Administrators.
- http://is-it-true.org/pt/

DShield
- Distributed Intrusion Detection System. Accepts firewall log excerpts from around the world and you can browse through activity reported to the system. Features a list of the "most wanted" abusive IP addresses.
- http://www.dshield.org/

Linux Security IDS
- An excellent source of IDS-related information, including security best practices, audit procedures, penetration testing, community information and more.
- http://www.linux-sec.net/IDS/