The Shape of Code

Rummaging around the web for empirical software engineering data, I found a survey of programming language usage in Japan. This survey (based on 505 projects in 24 companies) has Cobol in the number two slot for 2012, a bit higher than I would have expected (it very rarely appears at all in US/UK ‘popularity’ lists):

Language       Projects  
Java             822  28.2%
COBOL            464  15.9%
VB               371  12.7%
C                326  11.2%
Other languages  208   7.1%
C++              189   6.5%
Visual Basic.NET 136   4.7%
Visual C++       105   3.6%
C#               101   3.5%
PL/SQL            57   2.0%
Pro*C             23   0.8%
Excel（VBA）        18   0.6%
Developer2000     17   0.6%
ABAP              15   0.5%
HTML              14   0.5%
Delphi            11   0.4%
PL/I              10   0.3%
Perl              10   0.3%
PowerBuilder       7   0.2%
Shell              7   0.2%
XML                6   0.2%

A quick overview of Cobol for those readers who have never encountered it.

Cobol is a domain specific language ideally suited for business data processing in the 1960/70/80/90s. During this period computer memory was often measured in kilobytes, data came in an unbelievably wide range of different formats, operations on data mostly involved sorting and basic arithmetic, and output data format was/is very important. By “unbelievably wide range” think of lots of point-of-sale vendors deciding how their devices would write data to punch cards/paper tape/magnetic tape, just handling the different encodings that have been used for the plus/minus sign can make the head spin; combine the requirement that programs handle different data formats with tiny computer memory capacity, and you get data structure overlays that make C programmers look like rank amateurs, all the real action in Cobol programs occurs in the DATA DIVISION.

So where are we today? Companies use computers to solve a wider range of problems don’t they (so even if Cobol usage stayed the same its percentage usage should be low)? If point-of-sale terminals still produce a wide range of weird and wonderful data formats, isn’t it easy enough to write the appropriate libraries to convert (and we have much more storage these days)?

Why might Cobol still be so popular in Japan (and perhaps elsewhere, if anybody over 25 was included in the survey)? Some ideas:

• Cobol is still the best language to use for business data processing,
• the sample is not representative of the Japanese software development industry. As a government body perhaps the Information-Technology Promotion Agency primarily deals with large well established companies; the data came from a relatively small number of companies (i.e., 24),
• the Japanese are known for being conservative and maintaining traditions. Change is almost considered a necessity here in the West, this has led to the use of way too many programming languages in industry (I have previously written about what a mistake it is to invent a new language).