Almost 2000 years ago, the Roman architect Vitruvius recorded what makes a design good: durability (firmitas), utility (utilitas), and charm (venusta… - Hans van Vliet

Present-day applications are rather different in many respects. Present-day programs are often very large and are being developed by teams that collaborate over periods spanning several years. These teams may be scattered across the globe. The programmers are not the future users of the system they develop and they have no expert knowledge of the application area in question. The problems that are being tackled increasingly concern everyday life: automatic bank tellers, airline reservation, salary administration, electronic commerce, automotive systems, etc. Putting a man on the moon was not conceivable without computers.

Software engineering concerns methods and techniques to develop large software systems. The engineering metaphor is used to emphasize a systematic approach to develop systems that satisfy organizational requirements and constraints.

Computer science is still a young field. The first computers were built in the mid 1940s, since when the field has developed tremendously. Applications from the early years of computerization can be characterized as follows: the programs were quite small, certainly when compared to those that are currently being constructed; they were written by one person; they were written and used by experts in the application area concerned. The problems to be solved were mostly of a technical nature, and the emphasis was on expressing known algorithms efficiently in some programming language. Input typically consisted of numerical data, read from such media as punched tape or punched cards. The output, also numeric, was printed on paper. Programs were run off-line. If the program contained errors, the programmer studied an octal or hexadecimal dump of memory. Sometimes, the execution of the program would be followed by binary reading machine registers at the console.