Kotlin announced at Google I/O 2017

A new report released earlier this week estimates that Kotlin will surpass Java as the primary programming language used for Android apps by December 2018.

Until earlier this year, Kotlin was a little-known programming language [1, 2] that was built to run on the Java Virtual Machine, but one that could also be compiled to JavaScript and could interoperate with Java.

The programming language got a serious boost in the developer community when Google officially announced earlier this year, at the Google I/O 2017 conference, that Kotlin will become the first third-party supported programming language for Android apps, besides Java.

Kotlin adoption rate doubled since Google I/O

According to a report by Realm, a mobile development platform, the announcement skyrocketed Kotlin's adoption among Android app developers.

Kotlin's adoption rate for Android apps doubled from early May (Google I/O conference) from 7.4% to 14.7%, at the end of September.

If this growth continues, Kotlin will reach a 51% market share by December 2018, according to the Realm Report Q4 2017.

Kotlin estimated adoption rate

Among developers, Kotlin is considered Android's version of Swift, the easier-to-use programming language Apple introduced for iOS, and which ended up edging out the old Objective-C language.

Aftermath of the Oracle Java patent lawsuit

Google's announcement for supporting Kotlin on Android also comes after a long, drawn-out lawsuit that Oracle filed over Google's usage of some Java APIs inside Android, seeking huge payouts.

Back in 2016, right in the middle of the Oracle lawsuit, Google was looking for technologies for replacing Java on Android, and Kotlin was one of the top three favorites. The other two were Dart, a programming language created by Google, and Apple's Swift, which was both open source and the favorite, at the time, to replace Java. This time, Google is not using Kotlin as a base for the entire OS, but just as an alternative to writing Android apps.

"It’s clear: Java (on Android) is dying," the Realm team explains. "In fact, 20% of apps built with Java before Google I/O are now being built in Kotlin. Kotlin may even change how Java is used on the server, too."

"In short, Android developers without Kotlin skills are at risk of being seen as dinosaurs very soon," Realm experts add.

The countries where Kotlin is most popular right now are, in order, Germany, Japan, India, the US, and Brazil.