What determines a programming language’s success? What factors should we look at? Can we predict future trends? Does government support help a language? These intriguing questions were raised in this article, but were answered incompletely. Seventeen languages--Ada, Algol, APL, Basic, C, C++, Cobol, Eiffel, Fortran, Java, Lisp, ML, Modula, Pascal, Prolog, Scheme, and Smalltalk--were the third-generation general-purpose languages comprising the study. Scripting languages, such as Perl, PHP: hypertext preprocessor (PHP), and JavaScript, were excluded.

The authors identified 11 intrinsic factors, reflecting the properties of the language itself, and six groups of extrinsic factors, characterizing the historical context. They developed methods of quantifying these factors, which they elaborate upon on their Web site. Their model’s independent variables include the intrinsic factors and the past history of extrinsic factors, and the dependent variables include the current (or future) values of the extrinsic factors.

From the brief description, some of the sampling procedures raise questions. To collect information about grassroots support, they set up a Web-based survey form and invited software professionals to complete it. Apparently, the survey asked about language use in the years 1993, 1998, and 2003. No mention is made of the years of experience of the respondents, which would certainly affect the languages they knew. Younger respondents may not have been programming in the earlier years.

Some results are not clearly stated. They first conclude that the most important intrinsic factors are generality, reliability, machine independence, and extensibility. In the next paragraph, the authors state that, in a second model, “most of the time, the relationships in the first model didn’t show up in the second analysis.” They use a regression model to predict future trends. They validate their model by predicting the 2003 trends and comparing these with the observed values. However, the question they use is, “What percentage of people knew this programming language in 2003?” which is much less interesting than if that language were being used, not just known.

The figures included in the article show language usage by professionals, students, and companies. They are interesting, but the growth of the Web and the use of scripting languages, which were omitted from the study, will certainly have a great impact on future trends and limit this study’s value.