WireShark - The Wireshark Network Protocol Analyzer http://www.wireshark.org/ Windows - Apple - Linux - Others... 32 bit & 64 bit Axence NetTools - Axence NetTools Pro 4.0 http://www.axencesoftware.com/index.php?action=NTPro WINDOWS ONLY!!! NetTools Pro is a... FREE and comprehensive set of host monitoring, network scanning, security and administration tools, all with a highly intuitive user interface. *** REQUIRES ACTIVATION CODE *** WHICH IS FREE TOO!!! ;^) Just Sign Up... An email is set to you with the Registration Code!! The activation code is assigned to the computer that has been generated on. One can also activate another NetTools Pro on another computer. Just generate the activate code once again using your existing registration details. So, it looks like you can have multiple copies on various other computers... ;^) Net Tools - NetTools Version #5 http://mabsoft.com/nettools.htm Windows 98, NT, 2000, 2003, XP, Vista WINDOWS ONLY!!! With the 175+ tools it is a great collection of useful tools for network users. The size of Net Tools 5.0.70 is approximately 25 Mb. Net Tools is a comprehensive set of host monitoring, network scanning, security, administration tools and much more, all with a highly intuitive user interface. It's an ideal tool for those who work in the network security, administration, training, internet forensics or law enforcement internet crimes fields. Net Tools is mainly written in Microsoft Visual Basic 6, Visual C++, Visual C# and Visual Studio .NET. Just passing along some nice tools to help in debugging, etc... ;^) If any body else knows of any other FREE Software out there, feel free to add to this topic!!! :thumbup: Also, add your Pro's & Con's of the software too so that the 'community' all feels your joy :thumbups: & pain :argue:!!! "Most of the best things in Life are... FREE!!!" CHEERS!!!