Ensime
Ensime is a tool that provides an integrated development environment (IDE) experience for Scala and Java developers, primarily through text editors like Emacs, Vim, and Sublime Text. It offers features such as code completion, type inspection, refactoring, and debugging by integrating with build tools like sbt and Maven. Originally developed as an open-source project, it aimed to enhance productivity in lightweight editors by mimicking IDE capabilities without the overhead of a full IDE.
Developers should learn Ensime when working with Scala or Java in text editors to gain IDE-like features such as real-time error checking, navigation, and refactoring, which improve code quality and efficiency. It is particularly useful for those who prefer lightweight, customizable editors over traditional IDEs like IntelliJ IDEA or Eclipse, as it bridges the gap between minimal setups and advanced development tools. However, note that Ensime's development has largely ceased, so it may be less relevant for new projects compared to modern alternatives.