Aircrack ng is an 802.11 WEP and WPA PSK keys cracking program that can recover keys once enough data packets have been captured. It implements the standard FMS attack along with some optimizations like KoreK attacks, as well as the all new PTW attack, thus making the attack much faster compared to other WEP cracking tools. In fact, Aircrack ng is a set of tools for auditing .
AirSnort is a wireless LAN (WLAN) tool which recovers encryption keys. AirSnort operates by passively monitoring transmissions, computing the encryption key when enough packets have been gathered. 802.11b, using the Wired Equivalent Protocol (WEP), is crippled with numerous security flaws. Most damning of these is the weakness described in Weaknesses in the Key of RC4 by Scott Fluhrer, Itsik Mantin and Adi Shamir. Adam Stubblefield was the first to implement this attack, but he has not made his software public. AirSnort, along with WEPCrack, which was released about the same time as AirSnort, are the first publicly available implementaions of this attack.
AiroPeek NX captures and decodes packets, with special emphasis on the 802.11 protocol. AiroPeek NX receives all wireless LAN packets based on user settable configuration parameters and stores these packets in memory. For example, you can set a filter to capture all packets, only 802.11 authentication request frames, or all frames except beacons frames. Just about any combination of packet types and protocols are possible.