The trial version is fully functional for 14 days. It is the most powerful tool available for tracking down network-related configuration problems and analyzing application network usage. For documentation on TDI and the commands shown in TDImon, please see the Windows 2000 DDK , available for free download from Microsoft's web site. VisualRoute combines ping, whois, and traceroute all into one program with the point and click ease of a graphical interface. This sites been around a long time, and they do a great job.
Software is rated, and easy to find, but some days the site seems a little slow.
Literally hundreds of programs are available. You get mainframe quality tech support, and the best tools all from one source. Well organized, and fast. However, you may have to wade through a ton of end user software before you get to applications that you may actually find useful. NT Shareware One of our favorite sites.