Insecure.org: Top 75 Security tools
   List of 75 security tools based on a 2003 vote by hackers.
   http://www.insecure.org/tools.html

Metasploit Project
   Open-source platform for developing, testing, and using exploit code. Downloads and release notes. [Windows, Unix]
   http://www.metasploit.com/

Rootkit
   A program for hacking root.
   http://www.rootkit.com/