IntelliJ IDEA

IntelliJ IDEA is a code-centric IDE focused on developer productivity. IntelliJ IDEA deeply understands your code and gives you a set of powerful tools without imposing any particular workflow or project structure. IntelliJ IDEA is your dream pair-programmer who knows its way around the codebase, makes great suggestions right when you need them, and is always ready to help you shape your code.

Lightweight IDE for plain Java development, with XML and Groovy support, Most intelligent coding assistance, refactoring and code inspection tools, Integration with JUnit and TestNG, popular VCS tools, Ant and Maven, Supports Java, Groovy, XML, Scala, Clojure.

Enterprise edition is available and it has lot more feature than Open Source Edition