From the article:
"To lay the foundation for the research, the team first examined the volume of languages in the field, and found, unsurprisingly, that .Net, Java and ASP are the most widely used programming languages at 28.1%, 25% and 16% respectively. Legacy programming languages that have been around for decades, PHP (11%), ColdFusion (6%), and Perl (3%) rounded out the remaining field."
How did they determine the languages? This certainly differs from TIOBE's methodology (based on Google searches). The "unsurprisingly" seems suspect as well; I feel some of the selections *are* somewhat surprising.