IntelliJ IDEA
JetBrains' Java IDE, released in 2001. It was first to index the whole project and understand the code semantically, which made automated refactoring dependable rather than risky.
That remains the core value: rename a method and every call site, import, reflection string and test follows. Inspections warn about mistakes as you type, not at compile time. Community Edition is free under Apache 2 while Ultimate, with framework support and database tooling, is paid. The underlying platform is reused across the whole product family — PyCharm, WebStorm, GoLand, Rider, CLion and Google's Android Studio are the same IDE with different plugins. JetBrains also created Kotlin, originally to escape Java's limitations in their own codebase. The most common complaint is memory usage compared with VS Code.