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

I've uploaded my email address as an image to lower the amount of spam I receive
(1) Obsolete and no longer available.
(2) Acquired by Breach Security, Inc. in 2006.