GraalVM vs Quarkus: What are the differences?

Introduction

GraalVM and Quarkus are two popular technologies in the Java ecosystem. While both are widely used, they have distinct differences that set them apart. In this article, we will explore the key differences between GraalVM and Quarkus.

1. Code Execution: The primary difference between GraalVM and Quarkus lies in their main focus areas. GraalVM is primarily focused on providing a high-performance runtime for running polyglot applications, supporting various languages like Java, JavaScript, Python, and more. On the other hand, Quarkus is more focused on enabling resource-efficient, container-native, and cloud-native Java application development.

2. Ahead-of-Time (AOT) vs. Just-in-Time (JIT) Compilation: Another significant difference between GraalVM and Quarkus is their approach to compilation. GraalVM utilizes ahead-of-time (AOT) compilation, where the code is compiled before running, resulting in faster startup times and reduced memory footprint. In contrast, Quarkus relies on just-in-time (JIT) compilation, where the code is compiled during runtime, allowing for dynamic optimizations and potentially better overall performance.

3. Framework vs. Runtime: GraalVM is often referred to as a runtime, as it provides a virtual machine, compiler, and other tools for running various languages. It offers a polyglot runtime environment that allows developers to execute code in multiple languages on the JVM. On the other hand, Quarkus is primarily a framework that is built on top of existing Java frameworks like Eclipse MicroProfile and Spring to provide a streamlined and efficient development experience for building Java applications.

4. Native Image Support: One distinguishing feature of GraalVM is its native image support. It enables developers to compile Java applications into standalone, native executables that can be run without a JVM. This feature is particularly beneficial for building lightweight, fast-starting, and memory-efficient serverless or containerized applications. Quarkus, although it can utilize GraalVM's native image capabilities, focuses more on providing an efficient development experience using the traditional JVM-based approach.

5. Developer Experience: Quarkus is designed to optimize the developer experience by offering features like automatic hot-reloading, streamlined configuration, simplified dependency management, and faster development cycles. It aims to make Java development more efficient and productive. While GraalVM also provides developer tools like the Truffle framework and GraalVM native image, its primary focus is on language interoperability and runtime performance, rather than optimizing the development experience.

6. Target Use Cases: Due to their different focuses, GraalVM and Quarkus are aimed at different use cases. GraalVM is well-suited for scenarios that involve executing code in multiple languages, embedding languages in existing JVM-based applications, or running applications with strict memory or startup time constraints. On the other hand, Quarkus is particularly beneficial for building resource-efficient microservices, serverless functions, or cloud-native applications that leverage the capabilities of modern cloud platforms.

In summary, GraalVM and Quarkus differ in their main focus areas, compilation approaches, code execution capabilities, native image support, developer experience, and target use cases. While GraalVM emphasizes language interoperability and polyglot runtime performance, Quarkus focuses on enabling efficient cloud-native Java application development.