Ettercap is a suite for man in the middle attacks on LAN. It features sniffing of live connections, content filtering on the fly and many other interesting tricks.
It supports active and passive dissection of many protocols (even ciphered ones) and includes many feature for network and host analysis.
Category:   Software > Sniffing

Packet Analyzer Pro edition is an advanced packet analysis and sniffing tool with powerful protocol decodes capabilities. It captures and analyzes LAN traffic to help you identify network problems effectively
Category:   Software > Sniffing

Network stumbler for WaveLAN/IEEE wireless networking
Category:   Software > Sniffing

Packet Inspector is an advanced network traffic monitoring and analyzing, testing, and troubleshooting tool using packet analysis and protocol decode mechanisms. It captures all traffic over both Ethernet and WLAN (802.11a and b) networks and decodes all major and frequently used protocols including TCP/IP, UDP, HTTP, HTTPS, SMTP, POP3, TELNET, FTP, and so on. All information is displayed in simple English with an easy-to-use interface for anyone to master the tool with minutes of self-training. The flexible filters in Packet Inspector enable you to focus on the information that you are looking for.
Category:   Software > Sniffing

Ethereal is a free network protocol analyzer for Unix and Windows. It allows you to examine data from a live network or from a capture file on disk. You can interactively browse the capture data, viewing summary and detail information for each packet. Ethereal has several powerful features, including a rich display filter language and the ability to view the reconstructed stream of a TCP session.
Category:   Software > Sniffing