The rise of JVM languages: Kotlin, Scala, Groovy, and more

Introduction

As Java marks its 30th anniversary in 2025, it remains a foundational force in software development. However, one of its most enduring contributions is not just the language itself but the Java Virtual Machine (JVM). The JVM has paved the way for numerous modern programming languages by providing a stable, efficient, and interoperable runtime environment.

Over the years, developers have embraced JVM-based languages. These languages offer alternative syntax styles, functional programming paradigms, and dynamic scripting capabilities. At the same time, they maintain seamless compatibility with Java. This article explores the growth of JVM languages. It highlights Kotlin, Scala, and Groovy, along with other influential options such as Clojure, JRuby, and Jython. These languages have extended the reach of the JVM, empowering developers with increased flexibility and productivity.

Java and the JVM Languages: A Brief History

James Gosling and his team at Sun Microsystems developed Java in the early 1990s and officially released it in 1995. Its “write once, run anywhere” (WORA) principle revolutionized software development by enabling platform-independent applications through the JVM.

The JVM executes Java bytecode—an intermediate representation of Java source code—allowing programs to run on any system with a compatible JVM implementation. As developers recognized its potential beyond Java, new languages emerged, leveraging the JVM’s powerful runtime environment to introduce enhanced programming paradigms and features.

Over time, the JVM has evolved to support multiple enhancements such as Just-In-Time (JIT) compilation, improved garbage collection algorithms, and ahead-of-time compilation for performance optimizations. These improvements have solidified its position as a critical runtime environment for a variety of software applications, from mobile apps to large-scale enterprise systems.

Kotlin: A Pragmatic JVM Language Alternative to Java

Kotlin, created by JetBrains and officially launched in 2016, quickly gained traction due to its concise syntax, null safety, and modern language features. Designed for full interoperability with Java, Kotlin eliminates boilerplate code, making it a preferred choice for Android development and enterprise applications.

Google’s endorsement of Kotlin as an official Android language in 2017 significantly accelerated its adoption. Moreover, features like coroutines for asynchronous programming, extension functions, and improved type inference have further solidified Kotlin as a robust Java alternative.

Beyond Android, Kotlin is increasingly used in backend development with frameworks like Ktor and Spring Boot. Companies such as Pinterest, Trello, and Coursera have successfully integrated Kotlin into their technology stacks, highlighting its scalability and developer-friendly syntax.

Scala: Bridging Object-Oriented and Functional Programming in JVM Languages

Introduced in 2004 by Martin Odersky, Scala seamlessly integrates object-oriented and functional programming principles. Its expressive syntax and strong type system make it a powerful choice for building scalable applications.

One of Scala’s most notable applications is in Apache Spark, a leading framework for big data processing. By combining functional and imperative programming styles, Scala provides significant advantages for parallel and distributed computing, often surpassing traditional Java-based approaches in efficiency.

Scala is widely adopted by organizations working in data engineering, finance, and machine learning. Its compatibility with Java allows companies to gradually transition their existing codebases to a more functional paradigm while still leveraging the vast Java ecosystem.

Groovy: A Dynamic JVM Language Enhancing Java

First released in 2003, Groovy is a dynamically typed language designed to simplify Java development. With its support for scripting, closures, and metaprogramming, Groovy offers a flexible and developer-friendly syntax that closely resembles Java, easing adoption for Java programmers.

Groovy powers Gradle, a widely used build automation tool in Java and Android development. Additionally, it plays a crucial role in testing frameworks like Spock, which enhances Java application testing with expressive specifications.

Developers frequently use Groovy for scripting and rapid prototyping beyond build automation, which makes it a popular choice in DevOps and continuous integration workflows.Organizations often utilize Groovy for writing domain-specific languages (DSLs) tailored to specific business needs.

Clojure: A Functional Lisp for the JVM

Developed by Rich Hickey and officially released in 2007, Clojure is a modern Lisp dialect that runs on the JVM. It emphasizes immutability, functional programming, and concurrency, making it ideal for multi-threaded applications.

Clojure encourages a functional approach with pure functions and immutable data structures, unlike Java, which is primarily object-oriented. Its adoption has grown in fields like artificial intelligence, data processing, and financial computing due to its robustness in handling complex computations.

Clojure is particularly favored in startups and research-oriented projects that require high levels of concurrency and real-time data processing. Many developers appreciate its REPL (Read-Eval-Print Loop) environment, which allows for interactive programming and quick experimentation.

JRuby & Jython: Bringing Ruby and Python to the JVM

JRuby enables seamless integration with Java libraries and frameworks, making it an attractive choice for Ruby developers needing Java interoperability. Similarly, Jython provides Python developers access to Java’s scalability and enterprise features, making it valuable in various enterprise applications.

Web developers widely use JRuby, especially in applications that require both Ruby’s expressiveness and Java’s robustness. Scientific computing and financial services have adopted Jython, where developers benefit from Python’s simplicity alongside the power of Java-based tools.

Other JVM Languages

Several other JVM languages exist beyond the mainstream ones, catering to niche requirements:

• Frege: A functional programming language inspired by Haskell, introduced in 2011, designed to leverage JVM capabilities.
• JPHP: A PHP implementation on the JVM, introduced in 2013, allowing PHP applications to run in Java environments.
• Xtend: A Java-compatible language with advanced lambda expressions and template support, first released in 2012.

These languages highlight the JVM’s adaptability, ensuring developers have diverse options while benefiting from Java’s mature ecosystem.

Why the JVM Remains Relevant

Even after three decades, the JVM continues to be a dominant platform in software development. Its reliability, extensive library support, and strong developer community make it a compelling choice for modern programming languages. Performance optimizations, such as Just-In-Time (JIT) compilation and advanced garbage collection, further enhance its efficiency.

Additionally, the JVM remains central to cloud computing, microservices architectures, and big data processing. Its efficiency in handling complex workloads ensures the relevance of JVM-based languages in the evolving tech landscape.

Major cloud providers, including AWS, Google Cloud, and Microsoft Azure, offer strong JVM support, reinforcing its role in cloud-native development. Additionally, with frameworks like Spring Boot and Quarkus optimizing Java-based microservices, the JVM continues to evolve to meet modern software engineering demands.

Conclusion

The JVM has significantly evolved, extending beyond Java to support a diverse range of languages. Kotlin, Scala, Groovy, Clojure, JRuby, and Jython have enriched the ecosystem. They offer developers tailored solutions for various paradigms and application needs.

As Java celebrates its 30th anniversary, its influence extends far beyond its own syntax. The JVM is a cornerstone of modern software development. It fosters innovation and ensures a strong foundation for future advancements.