linux security concerned

Grsecurity Home
http://www.grsecurity.net/

Grsecurity ACL Documentation
http://www.grsecurity.net/gracldoc.htm

Grsecurity Online Document
http://online.securityfocus.com/infocus/1551

Doit ajou univ
http://doit.ajou.ac.kr/~kagi/res/?p=trusted_os

SE Linux (Security-Enhanced Linux)
http://www.nsa.gov/selinux/index.html

LIDS (Linux Intrusion Detection System)
http://www.lids.org

Flask (Flux Advanced Security Kernel)
http://www.cs.utah.edu/flux/fluke/html/flask.html

Medusa DS9 Security System
http://medusa.fornax.sk/

VXE (Virtual eXecuting Environment)
http://www.intes.odessa.ua/vxe/index.html

Openwall Project
http://www.openwall.com/

RSBAC for Linux
http://www.rsbac.de/

SE-Darwin
http://www.stosdarwin.org/

TrustedBSD Project
http://www.trustedbsd.org/

Immunix
http://www.immunix.org