The introduction of large scale integrated circuits brought computers onto peoples desks. Minicomputers had enabled departments to buy their own computers, but Personal Computers gave every individual computing power. This drastically changed the way operating systems had to be designed. Instead of the highly trained specialist needed to operate an IBM 360, potentially everybody could now use computers directly. Two operating systems from the early part of this period still exist. MS-DOS which IBM licensed from Microsoft was a operating system containing only the very basic features of a modern operating system. The operating system of the Apple Macintosh on the other hand was the successful attempt to create a user-friendly system which could be operated easily with a mouse using a graphical user interface. Due to its initial high price it has for a long time been relegated to niche applications like graphical design, publishing and advertising.
MS-DOS and UNIX are now trying to catch up with Apple's head start on the graphical user interface. Microsoft has produced Windows 95 which come close to the friendliness of Apple's operating system. Whereas UNIX based workstation manufacturers like Hewlett Packard and IBM with their UNIX variants are trying to catch up by providing graphical system administration tools.
This generation of computers also saw the growth of computer networks which allowed sharing of resources like disks and printers in the simple systems to the sharing of processing power in the advanced systems.
UNIX systems allow users on other computers to use them remotely, whereas MS-DOS and Apple systems can be only used if the user is present directly at the computer.
This also defines the applications UNIX is used for. Whereas MS-DOS and Apple systems are useful for word-processing and spreadsheets, UNIX computers are used for massive database operations and large calculations.
In this context it is important to mention two further high power systems. Digital's VMS is a very secure system originally developed for the VAX series of computers. Microsoft's Windows NT (which has only the user interface in common with Microsoft's Windows 95 or Windows 3.x) is another very secure system, but limited to about 4 processors per machine. The VMS system has a large user base due to its age, whereas the Windows NT system is not so widespread due to its limitations on remote usage and processing power. Digital which sell all three systems for its Alpha range of machines sells about 60% UNIX systems, 30% VMS systems and 10% Windows NT systems. In this range of high power machines the comparative user-unfriendliness of UNIX is weighed up by the fact that only a small number of experts work with these systems, whereas most users nowadays have desktop computers with Microsoft's Windows or Apple's Macintosh operating system.