IntelliJ IDEA has just gone open source:
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 the Apache 2.0 license. The Ultimate edition with full Java EE technology stack remains our standard commercial offering. See the feature comparison matrix for the differences.
I guess it was just a matter of time before IntelliJ either disappeared or went open source. Competing against free IDEs (Eclipse and NetBeans) in the development tools market has to be pretty tough.