IntelliJ IDEA Community Edition for Mac
IntelliJ IDEA lets you code without a hitch. It practices a non-intrusive, intuitive approach to help you write, debug, refactor, test and learn your code
Thanks to its deep understanding of languages and technologies, IntelliJ IDEA provides a second pair of hands for you when you need them.
IntelliJ IDEA Community Edition is the perfect choice for those working on pure Java/Groovy applications or doing Swing development.
IntelliJ IDEA Community Edition has all the crown jewels of IntelliJ IDEA, including various refactorings and code inspections, coding assistance, debugging, TestNG and JUnit testing; CVS, Subversion and Git support, as well as Ant and Maven build integration.
The IntelliJ IDEA Ultimate Edition extends the Community Edition by providing support for many web frameworks, additional languages and technologies and introduces many deployment options.
IntelliJ IDEA Ultimate Edition is a better choice for commercial usage given that all features are delivered in a complete package.
The complete breakdown of features included in IntelliJ IDEA Community Edition and IntelliJ IDEA Ultimate can be found in this comparison matrix.