What was the most popular programming language of 2015? According to the TIOBE Index, Java took that coveted spot, winning out over C, Python, PHP, and other languages. TIOBE updates its rankings once a month, based on search-engine data. Languages featured on its list must receive at least 10,000 hits for +”<language> programming” on Google, be Turing complete, and have an entry on Wikipedia. That’s not a hard requirement for popular languages such as Java to meet, although more obscure and research-oriented ones may struggle to qualify. “At first sight, it might seem surprising that an old language like Java wins this award,” read TIOBE’s note accompanying the data. “Especially if you take into consideration that Java won the same award exactly 10 years ago.” Yet Java remains essential not only for businesses, it continued, but also consumer-centric markets such as mobile development (i.e., Google Android). Given their ubiquity, it takes quite a bit of activity for any top-five language to rise (or fall) in the rankings. By contrast, even a few thousand developers deciding to embrace a lesser-utilized language such as Groovy or R can make all the difference to its visibility and rank. That’s why, the lower you go on TIOBE’s list, the more drastic the changes of fortune: Erlang, for example, went from 89th to 35th on the list in 2015, while Rust rose from 126th to 47th. That being said, even big languages can tumble. Objective-C tumbled from third place to 18th in the past 12 months, thanks to Apple’s decision to replace it with Swift. As the latter becomes the default language for iOS and Mac OS X programming, expect Objective-C to fall still further. In 2016, TIOBE expects that “Java, PHP (with the new 7 release), JavaScript and Swift will be the top 10 winners for 2016. Scala might gain a permanent top 20 position, whereas Rust, Clojure, Julia and TypeScript will also move up considerably in the chart.” In other words, no radical changes at the top of the rankings; but there could be some interesting activity among lesser-known languages.