- SecurityFocus
- Intrusion detection focus area; designed to assist discussion on security related topics, and provides a database of security knowledge and resources. It also hosts the BUGTRAQ mailing list. - 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.
- 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.
- 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.
- Linux Security IDS - A source of IDS-related information, including security best practices, audit procedures, penetration testing, and community information.
- LinuxSecurity IDS Resources - Collection of IDS-related resources made available by the linuxsecurity.com community.
- 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.
- 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.
- Talisker Security Wizardry - Large index of computer security resources, including a glossary of Intrusion Detection and Prevention systems.