Secuirty trivia on Linux

[hanasaki]

Security Linux?

Trivia but not Trivial!  Anyone care to share their experiences with the 
below?

does it work?
which is better for what and why?
which should be used together are complimentary vs overlapping

Please do separate experience vs. opinion.

Oh.. Anything important missing in the below list?


==== other stuff ===
kerberos

===== Application security tools ===
jail and chroot

========= kernel security tools ====
PAX

Adamantix
http://www.trustedlinux.org/
http://www.trusteddebian.org/

http://www.grsecurity.net/

http://www.nsa.gov/selinux/index.cfm

http://www.rsbac.org/

http://www.cs.virginia.edu/~jcg8f/GrsecuritySELinuxCaseStudy.pdf
http://www.nsa.gov/selinux/list-archive/0308/4941.cfm