Open Source | neumeier.org

Open Source

Auditing

Network

Nessus/Tenable Networks
NMap
Metasploit

Applications and Code

Features
Usability
Input Validation

Productivity Tools

Open Office link Documentation
Open Project link

Firewalls

Linux / IPtables link
Astaro link
Phion link
Cyberguard link
Juniper link
Fortinet link

IPTables

The linux kernel packet filter.

http://iptables.org