ModSecurity Handbook
The definitive guide to
ModSecurity (2010)
ModSecurity
Open source web intrusion detection and prevention engine (2002)
Feisty Duck
Fine technology books (2009)
PHP Traveller 1
PHP blog, code, libraries and articles (2002)
SSL Labs 3
A site dedicated to the research of SSL and TLS (2009)
Njam Njam 1
Cookery web site (2001)
 
Apache Security
The complete guide to securing your Apache web server (2005)
DGC 1
Intranet / Extranet / Document Management software (1999)
Thinking Stone 2
Web application security products and services (2004)
  
blog.ivanristic.com

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(1) Obsolete and no longer available
(2) Acquired by Breach Security in 2006
(3) Acquired by Qualys in 2010