4.3 SOFTWARE NOTES

Early operating systems were proprietary and device-dependent.
A device-dependent program is one that runs only on a specific type or brand of computer.

Proprietary software is privately owned and limited to a specific computer model.
The trend today is toward device-independent operating systems that will run on computers provided by a variety of manufacturers. Three basic categories of operating systems exist today. They are;

1. Standalone OS,
2. Network OS, and
3. Embedded OS

STAND-ALONE OPERATING SYSTEMS
A stand-alone operating system is a complete operating system that works on a PC. Examples of popular stand-alone operating systems include: Mac OS X, UNIX, Linux, MS-DOS and Windows (XP, Windows Vista, Windows 7, Windows 8, etc.)

NETWORK OPERATING SYSTEMS
A network operating system (NOS) is an operating system that supports a network and typically resides on the server. It enables the server to manage data, users, groups, security, applications, shared file and printer access among other networking functions. Some standalone OS can perform, these functions but network operating systems are designed specifically to support all sizes of networks.
Examples of network operating systems include Windows Server 2003, 2008, 2012,
Solaris, and Novell NetWare, UNIX server, and Linux server.

EMBEDDED OPERATING SYSTEMS
Start Screen, with live program tiles. An embedded operating system is an operating system that resides on ROM chips and typically used on handheld computers and small devices. Popular embedded operating systems today include Apple’s iOS, Google’s Android, Windows Embedded CE, Windows Mobile, Palm OS, Embedded Linux, Symbian OS, e.t.c.