Java, the most popular language, has an index rating of 15 percent, while C has a rating of 13.3 percent. SEE: Six in-demand programming languages: Getting started (free PDF) ...

Twitter, which runs using publicly-facing publishing and search engine functions, is developed in code written in Scala, a concise 18-year-old programming language, compared to Python, a 31-year ...

Other languages that made significant gains over the past year include MATLAB, which rose from 18th to 11th place, and key Android app programming language, Kotlin, which rose from 39th to 31st place.