Eavesdrop is an application for listening in on TCP conversations on the network your computer is attached to. See Notes for Newbies if you have not worked with a network sniffer before. I strongly suggest you look into other applications, such as tcpdump (available in Mac OS X 10.3 already) and Ethereal (available through fink and probably other sources).
Version 0.5a4:
Originally written by Eric Baur, now maintained by William Entriken. Licensed under GPL, version 2.
This project runs on modern versions of Xcode, but produces many deprecation warnings.
The latest download binary is published here https://github.com/fulldecent/eavesdrop/releases