Nice collection of security tools

There are numerous security-related tools one can find nowadays on the internet. Furthermore, collections of tools come bundled in all-in-one solutions such as the Linux distro BackTrack.

Sifting through these is not easy, especially if you don't know which one are the most interesting and the most effective. A list of some is included here, feel free to add to the list.

This is not an exhaustive list of penetration testing and such tools by any means. Just a few handpicked utilities and resources that are recommended if not essential for your network's security. Here is the list:

Scanning/mapping tools
Allow you to scan targets, map networks, detect vulnerabilitities: wireshark, kismet, nmap, amap, nessus, satan

Multipurpose/suites
backtrack, cain

SQL Injection/fuzzers
Allow for SQL injections, exploiting poorly designed applications and buffer overflow problems
absinthe, bed

Exploits for privilege escalation
Allow for gaining root/administrator privileges: openssl scanner, metasploit

Defense/detection
Allow for proactively defending from various threats: iptables, snort

Cracking
Allow for making use of resources that are not yours, various tools exist, depending on target: WEP/WPA, Linux, Windows, etc.

Backdoors
Allow for maintaining access after breaking in, without having to break in again: matahari, subseven, SilentDoor, SafeBreaker

Rootkits
Allow for maintaining stealthy access by preventing being detected, various tools for *nix/win32 flavours, browsing this plentiful collection is strongly advised

Forensics
Allow for undeletion of deleted files, partitions and more: sleuthkit, foremost