How long do programming languages stay popular?

Programming languages come and go. Some are more popular than others. Some are popular longer than others.

So just how long do programming languages stay popular?

I mean this in a very specific sense, one that is different from the general popularity of programming languages. The folks at www.tiobe.com have studied popularity in great detail, but they are considering all uses of programming languages.

There are many languages. Some, like COBOL and Fortran have been with us for ages. One can argue that their popularity has extended from the 1950s to today, or over sixty years. But much of the demand for those languages is existing systems. Very few people today (I believe) start new endeavors with COBOL.

If we look at the languages used for start-ups and new projects, we see a pattern for the popularity of languages. That pattern is:

1950s: IBM System/360 Assembly
1960s: IBM System/360 Assembly, COBOL, Fortran
1970s: COBOL, Fortran, RPG
1980s: PC Assembly, BASIC, C
1990s: C++, Visual Basic, Java, Perl
2000s: Java, C#
2010s: Python, Ruby, JavaScript

This list is not comprehensive. I have kept the list small, to focus on the big languages. There were lots of other languages (Dibol, Focal, PL/I, Ada, Awk, Forth, etc) that were used for projects, but they were never mainstream. Apologies if I have omitted your favorite language.

Looking at my selected "winners" of languages, we see a pattern: Languages are popular (for new projects) for a period of perhaps ten to fifteen years. Early languages such as IBM System/360 Assembler and COBOL have longer lives.

BASIC is an interesting case. It had popularity in the 1980s and then a second life as Visual Basic in the 1990s. Its first incarnation was as a general-purpose language for programming the original microcomputers (Apple II, Commodore PET and C-64, Radio Shack TRS-80, etc.). Its second life was as a general-purpose language for Windows.

All of these languages had a heyday of a little more than a decade. COBOL and Fortran fell to BASIC. BASIC mutated into Visual Basic and eventually fell to Java and C#. Perl emerged, had success, and has been replaced by Python.

Which leads us to an interesting point. We're now at Java's twentieth anniversary, and C#'s fifteenth. According to my theory, these languages should be on the wane -- for new projects. Certainly there are lots of existing Java systems and lots of existing C# applications. But what languages are people using for new systems?

Informal conversations with fellow developers indicates that new projects are using neither Java nor C#. Instead, new projects (or start-up companies) are using Python, Ruby, and JavaScript.

It may be, in the near future, that we will see conversion projects from Java and C# to newer languages.