The Free On-line Dictionary of Computing (30 December 2018):

Windows 2000
NT5
W2K
Win2K
Windows 2K
Windows NT 5

    (Win2k, W2k, NT5, Windows NT 5.0) An
   operating system developed by Microsoft Corporation for
   PCs and servers, as the successor to Windows NT 4.0.
   Early beta versions were referred to as "Windows NT 5.0".
   Windows 2000 was officially released on 2000-02-17.

   Windows 2000 is most commonly used on Intel x86 and
   Pentium processors, with a DEC Alpha version rumoured.
   Unlike Windows NT 4.0, Windows 2000 is not available for
   PowerPC or MIPS.

   Windows 2000's user interface is very similar to Windows
   95 or Windows NT 4.0 with integrated Internet Explorer, or
   to Windows 98.

   It is available in four flavours:

   - Professional: the client version, meant for desktop
   workstations, successor to Windows NT Workstation.

   - Server: "entry-level" server, designed for small
   deployments, and departmental file, print, or intranet
   servers.

   - Advanced Server: high throughput, larger scale servers
   and applications, and small to medium scale websites.

   - Data Center Server: software for large-scale server
   clusters (in development as of 2000-03-14).

   New features in Windows 2000 include:

   - Active Directory.

   - Greatly improved built-in security mechanisms, including
   Kerberos-based authentication, public key support, an
   encrypting file system, and IPsec support.

   - Integrated web browser - Internet Explorer 5.0.

   - Integrated web server - IIS 5.0

   - Terminal services for displaying application interfaces on
   remote computers (similar to X-Windows).

   - File protection that prevents user programs from
   accidentally deleting or overwriting critical system files.

   - Improved hardware support, including Plug-and-Play, DVD,
   IEEE-1394 (FireWire), USB, infra-red, PCMCIA, ACPI,
   laptop computers.

   - Improved user interface, including a single point to control
   the entire system.

   - Improved management tools, including remote administration.

   Minimum system requirements, according to Microsoft, are
   Pentium-133 MHz CPU, 64 MB RAM, 650 MB of hard
   disk space.  These are for W2K Professional, others require
   more.

   Many operating systems compete with Windows 2000, including
   the Apple MacOS, Linux, FreeBSD, OpenBSD, NetBSD,
   Sun Solaris, IBM AIX, Hewlett-Packard HP-UX, SGI
   Irix.  Novell's NDS also provides a service similar to
   Active Directory.

   Windows 2000 will be followed by Windows XP Professional and
   Windows 2002.

   (http://microsoft.com/windows2000/).

   (2002-01-28)