The first intelligent Java IDE that since the year 2000 has brought clever code assistance, refactorings or code analysis to the Java masses has been open-sourced. Starting with the upcoming version 9.0, IntelliJ IDEA will be offered in two editions: Community Edition and Ultimate Edition. The Community Edition focuses on Java SE technologies, Groovy and Scala development. It's free of charge and open-sourced under Apache 2.0 license. The Ultimate edition with full Java EE technology stack remains our standard commercial offering.
Surprised I haven't see this yet. Mostly just for JVM developers (Java, Groovy and Scala) but has the possibility of extending to other languages soon.
(If this goes better int he Java Programmers forum feel free to move it)