Kismac
KisMAC is a free, open source wireless stumbling and security tool for Mac OS X.
Overview
- Uses monitor mode and passive scanning
 - KisMAC supports many third party USB devices: Intersil Prism2, Ralink rt2570, rt73, and Realtek rtl8187 chipsets. All of the internal AirPort hardware is supported for scanning
 
Features
- Reveals hidden / cloaked / closed SSIDs
 - Shows logged in clients (with MAC Addresses, IP addresses and signal strengths)
 - Mapping and GPS support
 - Can draw area maps of network coverage
 - PCAP import and export
 - Support for 802.11b/g
 - Different attacks against encrypted networks
 - De-authentication attacks
 - AppleScript-able
 - Kismet drone support (capture from a Kismet drone)
 
Supported hardware chipsets
- Apple AirPort and AirPort Extreme (dependent upon Apple's drivers)
 - Intersil Prism 2, 2.5, 3 USB devices
 - Ralink rt2570 and rt73 USB devices
 - Realtek RTL8187L USB (such as the Alfa AWUS036H, which does not work on Mac OS 10.6.7 or later)
 
Crypto support
- Bruteforce attacks against LEAP, WPA and WEP
 - Weak scheduling attack against WEP
 - Newsham 21-bit attack against WEP