Wireshark is the world's foremost network protocol analyzer, and is the de facto (and often de jure) standard across many industries and educational institutions.

New features:

The "About" box finally displays version 1.0.

Wireshark now supports custom columns.

This release includes an experimental Mac OS X package.

Full changelog over here.

Program Information Category: Internet and communication Type: Free Version: 1.0.1 Size: 21.1MB Works on: Windows, Mac Product page: here