If you determine that your network needs one or more dedicated servers, the next step is to determine what network operating system those servers should use. If possible, all the servers should use the same NOS so you don't find yourself awash in the conflicting requirements of different operating systems.
Although you can choose from many network operating systems, from a practical point of view, your choices are limited to the following:
Windows Server 2003 (or its forthcoming replacement, Windows Server 2007)
Novell NetWare
Linux or another version of UNIX
For more information, see Chapter 7.