The TIOBE index for August 2017 shows Java as the world’s number one programming language in terms of popularity, but interest continues to fall. However, studying the top 20 rankings, it seems that is the same trend with all of the major programming languages. So where are developers going? TIOBE reports that several new languages are filling the gap by increasing their share of the programmer mindset.

Java still holds twice as much share of the index as its next most popular rival, C, but both languages have seen significant drops in their popularity in the last year. Another twelve of the languages in the top 20 have also seen a drop, while the combined increase of 1.34% in the remaining six (Visual Basic .NET, R, Go, MATLAB, Scratch and Dart) falls far short of the drop of 6.05% incurred by Java alone.

TIOBE sees an upsurge of interest in a group of new languages, calling out Crystal, Kotlin, Clojure, Hack and Julia for special mention. Their overall share of the index is small (all less than 1%) but the speed of their uptake is enough to take notice. Ruby cousin Crystal in particular leapt from position 60 to 32 in one month. Crystal advocate Santiago Palladino tweeted that this was not surprising, now that more companies are using Crystal in production environments.

A factor in the rise of Jetbrains’ Kotlin JVM language is probably Google’s adoption and advocacy of the language for Android development in May of this year. A Google trends search shows a sharp upsurge in Kotlin around that time. The Spring Framework also announced support for Kotlin in January.

Hadi Hariri from Jetbrains concurred on the influence of Google, but stated that Kotlin has been steadily on the rise even before the announcement. He told InfoQ:

We assume the spike on the TIOBE index has been associated with the Google I/O announcement. Independent of this we've also seen an increase of Kotlin adoption since the time of release which was over a year ago, and an 8-fold increase in Kotlin lines of code on GitHub projects from the release of 1.0 to 1.1 (released in February this year).

While seeing some relevance in Kotlin’s rank in the TIOBE index, Hadi says that ultimately "the continuous increase in Kotlin adoption is what is more important."

The TIOBE Programming Community Index (to give it its official title) is published monthly and reflects the relative popularity of programming languages. It derives the rankings from the number of skilled engineers world-wide, courses and third party vendors using data collected from the main search engines. This month’s edition contains extra analysis of trends over the last 12 months. Languages must be Turing Complete to be included.