A IP Subnet Calculator that fits on one diskette and doesn't require supporting DLLs or ActiveX controls, which means it can be used without running Setup. Results are shown in binary octets to help in understanding subnetting, and can be printed or copied to the clipboard. Not that creating logon scripts is hard to do, but everyone knows it's more fun to click and drag. In a few seconds, you produce a high quality map of a network, print it or save it to a floppy and modify it. 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.