The aircrack-ng software suite includes:

Name	Description
aircrack-ng	Cracks WEP and WPA (Dictionary attack) keys.
airdecap-ng	Decrypts WEP or WPA encrypted capture files with known key.
airmon-ng	Placing different cards in monitor mode.
aireplay-ng	Packet injector (Linux, and Windows [with Commview drivers]).
airodump-ng	Packet sniffer: Places air traffic into PCAP or IVS files and shows information about networks.
airtun-ng	Virtual tunnel interface creator.
airolib-ng	Stores and manages ESSID and password lists; Increases the KPS of WPA attacks
packetforge-ng	Create encrypted packets for injection.
Tools	Tools to merge and convert.
airbase-ng	Incorporates techniques for attacking client, as opposed to Access Points
airdecloak-ng	removes WEP cloaking from pcap files
airdriver-ng	Tools for managing wireless drivers
airolib-ng	stores and manages ESSID and password lists and compute Pairwise Master Keys
airserv-ng	allows you to access the wireless card from other computers.
buddy-ng	the helper server for easside-ng, run on a remote computer
easside-ng	a tool for communicating to an access point, without the WEP key
tkiptun-ng	WPA/TKIP attack
wesside-ng	automatic tool for recovering wep key.

what is aircrack

Aircrack-ng is a network software suite consisting of a detector, packet sniffer, WEP and WPA/WPA2-PSK cracker and analysis tool for 802.11 wireless LANs. It works with any wireless card whose driver supports raw monitoring mode (for a list, visit the website of the project or and can sniff 802.11a, 802.11b and 802.11g traffic. The program runs under Linux and Windows; the Linux version has been ported to the Zaurus and Maemo platforms, and a proof-of-concept port has been made to the iPhone.
In April 2007 a team at the Darmstadt University of Technology in Germany developed a new attack method based on a paper released on the RC4 cypher by Adi Shamir. This new attack, named 'PTW', decreases the number of initialization vectors or IVs needed to decrypt a WEP key and has been included in the aircrack-ng suite since the 0.9 release.
Aircrack-ng is a fork of the original Air crack project.