KisMAC supports several third party PCMCIA cards – Orinoco, PrismII, Cisco Aironet, Atheros and PrismGT. USB Prism2 is supported as well, and USB Ralink support is in development. All of the internal AirPort hardware is supported as well.

System Requirements

• Mac OS 10.4
• A Mac with a supported PCMCIA, USB or internal AirPort

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,n
• Different attacks against encrypted networks
• Deauthentication attacks
• AppleScript-able
• Kismet drone support (capture from a Kismet drone)

Active mode, also referred to as managed mode, sends probe requests and is pretty boring.
Passive mode is more commonly known as monitor mode, and passively monitors what’s already in the air without interfering in it.
Active attacks like deauth and reinjection (where supported) require your device to be in monitor or passive mode.

You can download KisMAC here:

KisMAC

Or read more here.