I'm kind of familiar with heterogenous networks. We've got Windows workstations and back-end servers, some single-purpose *nix boxes for things like document archival and retrieval, and an IBM mainframe. And I'm familiar with the the problems involve in getting it to all work together.
"Simple workgroup networking" between a couple of computers at you home is one thing. When it has to scale to several thousand, and pass an FDIC security audit it gets a little more complicated.
"Simple workgroup networking" between a couple of computers at you home is one thing. It was a simple example. OS X is designed to run networks of Windows systems, or run nicely under Windows networks, and of course it plays nice with the other UNIXes.