ABSTRACT
Computer systems were developed with an emphasis on hardware; the software was developed to let the hardware function in the best possible way. In systems, however, hardware is designed to meet software constraints and demands. Application control software consists of software that is provided by the computer manufacturer and software developed by the user which has become part of the control package. User-developed application software can be written in different languages depending on the type of computer. Support software is software that supports the user in his communication with the operating system. It provides valuable tools for efficient use of and communication with the computer. An on-line computer system communicates with the process on a real time basis via the process interface. Increasingly, software development is becoming the cost determining factor in a computer system. Some computer manufacturers already quote prices for system software packages that exceed the hardware cost.
