Why are there so many different programming languages?

Avi Kak

As is the case with most things in life, I believe there are multiple reasons for why we have so many programming languages. Here are what I believe to be the more significant reasons:

  • Programming languages vary with respect to the speed with which programs written in them can be executed. So if you have a real-time application, you'd choose a language that would be capable of delivering results under the applicable time constraints. So for a problem in dynamic control, you might choose, say, C over C++ or Java.
  • Certain application domains require programming languages that are specifically targeted for those applications. Cobol, for example, represents a language that was developed specifically for business applications. It is easy to learn by people without advanced degrees in computer science and it is efficient for what it was designed to do.
  • Much early programming dealt with solving numerically intensive problems, such as problems encountered in scientific calculations. Fortran emerged as a favorite of many for such applications. I believe it continues to be a widely used language for solving numerically intensive problems on supercomputers.
  • Many programming languages that have emerged from academic laboratories are a result of researchers trying mimic certain aspects of human cognition. Languages like Lisp and Prolog fall in this category.
  • Another reason for why we have so many programming languages is purely evolutionary. Consider, for example, the evolution from C to C++ and then on to Java. As it began to be realized that we needed richer representations for our concepts and as we sought ways to make large programs more easily extensible and maintainable, the concepts of object-oriented programming came into existence. Then as we better understood what was meant by object-oriented programming through pioneering languages like Smalltalk, C led to the development of C++. And then as it dawned on us that the wide generality of C++ (with regard to inheritance, operator overloading, and other issues) could become a liability in some cases, Java emerged.
  • As the role of computers as "information presentation devices" proliferated in the society, there emerged a concomitant need for languages designed specifically for formatting the visual display of information. Languages such as HTML, XML, and their variants are fulfilling those needs.
I suppose what it all means is that as we continue to deploy computers for solving previously unaddressed problems, we will try to use the languages we already know. But should they fall short of our needs for whatever reason, we as a society of programmers will invent new languages.