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Developers favor JVM languages for mobile, enterprise

A recent RedMonk report finds more developers use programming languages that run on the Java Virtual Machine to build mobile and enterprise apps.

Languages that run on the Java Virtual Machine have lined up well with mobile app developers, alongside the usual code suspects.

JavaScript, Java, Python, PHP and C# top RedMonk's latest list of programming languages, ranked by code usage (GitHub pull requests) and discussions (Stack Overflow Q&As). C++, CSS, Ruby, C and Objective-C round out the top 10. But a host of JVM languages rank in the middle of the pack and are on the move up the list.

The JVM supports a host of programming languages, such as Kotlin, Groovy, Scala and Clojure, along with JRuby and Jython, as well as more obscure languages such as BeanShell, Pizza, Pnuts and Xtend. Scala (ranked 12th), Clojure and Groovy (tied at 21st) advanced in the RedMonk rankings, while Kotlin -- one of the hottest languages around -- fell back one spot to 28th.

Bright future for Kotlin, Swift for mobile OS development

Kotlin is especially popular with mobile app developers as a preferred language for Android application development due to its clean, modern design, wrote Stephen O'Grady, analyst at RedMonk, based in Portland, Maine, in a blog post.

Scala had dropped for three consecutive quarters prior to this latest ranking, although the drops were rather small. The causative factors behind Scala's past declines are unclear, but likely involve competition not only from Java but from other JVM languages such as Clojure, Groovy and even Kotlin.

"Scala had its day in the sun, but it seems to be suffering from growing pains and unable to move under the resistance of its own considerable weight," said Cameron Purdy, CEO of, a Lexington, Mass., software startup in stealth mode, and formerly senior vice president of development at Oracle.

Ten programming languages

Swift, a newer language to build iOS applications, also slid one slot out of a tie with Objective-C, but still enjoys increased attention from developers. IBM and others have pushed Swift as a server-side language.

Like Kotlin, Swift appeals to developers as a language that hides the ugliness of a legacy platform, although it drags a ton of luggage from various legacy Apple technologies that feel less clean, Purdy said.

"If I were a developer starting out today, I'd prioritize Kotlin and Swift for Android and iOS development, with JavaScript or TypeScript for the browser," he said. "Kotlin should also suffice for the back end."

Reading the tea leaves

Charles Nutter, Red HatCharles Nutter

Other industry experts suggest the ebbs and flows of such language popularity rankings are nothing more than periodic changes in the schemes of software development.

As programmers change development projects, they'll shift from "vanilla Java" to Kotlin if they're doing Android development, or to Groovy for development with Grails, or to Clojure or Scala for various functional programming work, said Ted Neward, director of developer relations at Smartsheet, Bellevue, Wash.

The more Java improves, the less these other 'Java++' languages have compelling enough differences to justify the overhead of using something other than Java.
Charles Nuttersenior principal software engineer, Red Hat

"This is much like trying to read the tides by marking the waves on the side of the pier over a five-minute period," he said. JVM languages in general have carved out a niche within the broader Java world, which is viable because that world is so large. "If anything, it signals that these languages are reaching a level of maturity and acceptance within the ecosystem," he said.

Meanwhile, recent improvements in the Java language, such as lambdas in Java 8 and local variable type inference in Java 11, take some steam away from JVM alternatives, said Charles Nutter, co-lead of the JRuby open source project and a senior principal software engineer at Red Hat.

"The more Java improves, the less these other 'Java++' languages have compelling enough differences to justify the overhead of using something other than Java," Nutter said.

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