What is junit-framework?

JUnit is the standard testing framework for Java and the JVM. When developers write automated tests to verify that their code works correctly, JUnit is usually the tool they use to do it. This repository is the official home of the framework, covering three related components: JUnit Platform, JUnit Jupiter, and JUnit Vintage. JUnit Platform is the foundation layer. It defines the interfaces and infrastructure that testing tools and IDEs use to discover and run tests on the JVM. JUnit Jupiter is the modern API that developers use to write new tests, including the annotations and programming model that most people associate with JUnit 5 and later. JUnit Vintage exists for backward compatibility, allowing older tests written with JUnit 3 or 4 to run alongside new ones without rewriting them. The framework also supports Kotlin, so developers using Kotlin on the JVM can write tests using the same infrastructure. It integrates with build tools like Gradle and Maven, and with IDEs from JetBrains (a listed sponsor) and others. Code coverage can be generated through JaCoCo, and the project uses Develocity for build caching and predictive test selection to speed up CI runs. The latest stable release at the time of the README is JUnit 6.0.3, published in February 2026. A release candidate for 6.1.0 was available in April 2026. Building the project from source requires JDK 25 and uses the Gradle Wrapper. The artifacts are published to Maven Central and can be added to any Java or Kotlin project through standard dependency management. The project is actively maintained with continuous integration, community contributions accepted, and questions supported through Stack Overflow and GitHub Discussions.