In response to my previous post, I made a new word cloud for the top 25 programming languages in the QSM historical database from 2008 to present.

One striking difference between this word cloud and the last week's is that the font sizes are much smaller, due to the smaller sample size. Since word clouds use font size to represent size within a sample, this is expected since the entire QSM database is larger than the sample from 2008 to present. 

Unlike last week's cloud, Java is the predominant programming language since 2008. Java represents 26% of the sample since 2008 while COBOL, the #1 programming language in the entire database, holds only 11% of this sample. According to Langpop.com, a site which ranks the popularity of programming languages using search results, Java ranks second in the Normalized Comparison chart, just below C.  

In Programming Language Trends: An Empirical Study, a paper from the New Jersey Institute of Technology, the authors attempt to predict the popularity of programming languages by using regression analysis which focuses on intrinsic and extrinsic factors.  

Since I began working with SLIM-Metrics and the QSM historical database, I've been interested in unique ways to present information.  I've written before about how others pair data and design to visualize patterns, but this is my first attempt: a word cloud.  

A word cloud is a graphical representation of how often a word is used within a sample.  The larger the font in the word cloud, the more often it is used in the sample.  Word clouds are a great tool for displaying sensitive data without having to use numbers.  The above word cloud visualizes the entire QSM database, going back three decades.

What I like about this visualization is that at a glance, you can tell that more projects use PL/1 than Natural, simply by examining font size.  Even without knowing exactly how many Java projects are in the QSM database, you can still determine that it's more than Visual Basic, but less than COBOL. 

Unsurprisingly, COBOL still has a large market share in the QSM database.  Most COBOL projects completed after 2000 were maintenance projects, not new development. 

On Linked In, Peter Hill reports on current "programming languages of choice" in the ISBSG database:

"Java and C# .Net are now the languages of choice in the projects that the ISBSG receives. COBOL has slumped to 12% (it used to be 38%) and Visual Basic has dropped back to 5% after peaking at 15%."

I thought it might be interesting to find out how the "market share" for popular programming languages has changed over time. The first task was to stratify Business projects from the QSM database into 5 bins using the year the systems were put into production. Only medium and high confidence projects with language data were used. Sample sizes ranged from about 600-1200 projects with most year bins containing around 1000 projects.

For each year bin, I determined the "market share" (% of total projects in each bin) for various programming languages. Each bin spans 5 years (1985-1990, 1990-1995 and so on). 

The durability of COBOL surprised me a bit. The vast majority (>75%) of the COBOL projects put into production between 2005 and 2010 were major/minor enhancements of existing systems or maintenance releases, but despite their dwindling market share, COBOL systems appear to be the Energizer Bunnies of the software world - they just keep going, and going, and going....