SwiftCrack is a wireless LAN (WLAN) tool which recovers encryption keys. SwiftCrack operates by proactively monitoring transmissions, injecting traffic with known key streams, computing the encryption key when enough packets have been gathered.
YAWCU is a wireless LAN (WLAN) capture + WEP cracking utility. It can crack 64/128 Bit WEP keys on IEEE 802.11b/g networks by monitoring WLAN traffic and computing the resulting WEP key once enough packets have been gathered