One of the known similarities of UNIX and Windows is that they ..

What is the difference between unix and windows operating systems? - Operating System

Consider at least 2 flavors of Linux/UNIX and Windows 2000 and ..

(Note: Theinformation presented is valid for both NT Version 4 and Windows 2000.)Windows NT/2000 is built on a new operating system code base, similar in many ways towell-established OSes such as UNIX and VMS, and very different from Microsoft'sDOS/Win16/Windows 9 platforms.

Compare Linux and Windows 2000; Linux /unix …

Recall that we defined "Unix" to be a family of systems. If you were to enumerate what constitutes "Unix" today, you would get maddening diversity: in architectures, interfaces, flavors, distributions, and many more. Even apparently similar Unix systems, such as two Linux distributions, might be different enough to warrant considerable extra "work", if an attacker were to create (the easy part) and deploy (the hard part), say, a virus. Creating malware, as we have seen, is a technical problem, easily solved on any platform. Spreading malware involves operational and situational issues, which are apparently less of an obstacle on Windows than any other platform.

I have found there are more similarities between Linux and Windows once you put a GUI in front of Linux than differences. I think some things are unnecessarily difficult (i.e. sendmail config) than need be.