BlueJ vs IntelliJ IDEA

BlueJ is a free development environment for building Java programs, designed for beginners and teaching. It runs on Windows, macOS and Linux, with current downloads requiring a 64-bit operating system. Its interactive tools let users create and inspect objects, call methods, and evaluate Java expressions without compiling. In the editor, scope highlighting distinguishes code blocks and can help reveal misplaced curly brackets. BlueJ 6.0.0 added Kotlin editing and execution, though some Kotlin features, including code completion, are not supported. Documentation includes a Git teamwork tutorial for BlueJ 4 and later. Third parties can add functionality through an extensions API; the listed extensions page covers BlueJ 4 and older, while BlueJ 5.0.0 rewrote the API. The free Blueroom site offers teaching resources for educators. BlueJ directs software questions to its FAQ, technical support contact and bug database, and says it aims to respond to technical support requests within one working day.

IntelliJ IDEA is an IDE for professional Java and Kotlin development, available on Windows, macOS, and Linux. It offers context-aware completion, static analysis, and automated refactoring. The JVM debugger includes breakpoints, variable inspection, expression evaluation, and step-by-step execution. Gradle and Maven integrations cover building, packaging, testing, and deployment, while version-control support includes Git, Mercurial, Perforce, and Subversion. Users can process GitHub pull requests in the IDE, and plugins from JetBrains Marketplace add support for other languages, frameworks, and technologies. Core Java and Kotlin functionality remains free after the included 30-day Ultimate trial ends. The Ultimate subscription adds advanced tools and integrations and costs $100.00 for the first year, $199.00 for the second year, and $159.00 per year from the third year onward. Listed minimum hardware is a 4-core x86_64 or arm64 CPU, 8 GB total RAM, and 10 GB of disk space. Users can choose in IDE settings whether to share anonymous usage data.