Well, except for the Mac-only IDE (AppCode I think it's named), the other IDEs are just tweaked IntelliJs with stripped down configurations and language specific plugins.
Those plugins can be installed and used in IntelliJ itself, so you can have Java/Ruby/Python/PHP/Javascript/etc support, all in one.
Those plugins can be installed and used in IntelliJ itself, so you can have Java/Ruby/Python/PHP/Javascript/etc support, all in one.