IntelliJ IDEA — The Most Intelligent Java IDE

IntelliJ IDEA is a code-centric IDE focused on developer productivity. The editor deeply understands your code and knows its way around the codebase, makes great suggestions right when you need them, and is always ready to help you shape your code.

Blazing Fast and Smart Code Completion

IntelliJ IDEA offers smart, type-aware code completion. It knows when you may want to cast to a type and is also aware of the run-time type checks that you made, after which you can perform cast and method invocation in a single action!
New in IntelliJ IDEA 11 — code completion auto-invoked instantly as you type.

Easier Multilanguage Editing

IntelliJ IDEA easily recognizes one language inside another — language injections, such as SQL inside a Java, HTML inside JavaScript, etc. For injections the editor provides appropriate coding assistance inline and a dedicated injection fragment editor.

These are just 2 things out of dozens that make IntelliJ IDEA different.

Community Edition — Free and Open IDE for Java

IntelliJ IDEA Community Edition is the open source version of IntelliJ IDEA, a premier IDE for Java, Groovy and other programming languages.

* Intelligent code editor understanding your code, with refactorings, code inspections, intention actions, easy navigation and full Java 7 support.
* JUnit and TestNG integration and a convenient test runner UI.
* Maven and Ant-based project setup and building.
* Comprehensive Groovy programming language support plus plugins for Scala and Clojure.
* Google Android development including latest SDK support.
* Unified UI and experience for most popular version control systems: Subversion, Git, Mercurial and CVS. Visual merge, diff and changelists.
* Powerfull XML editor with XML-Java interoperability.
* The Swing UI designer for developing Java desktop applications.

Performance
Performance improvement is a neverending task. IntelliJ IDEA's new editor architecture provides better responsiveness and lag-less typing even in huge files.

Faster indexing is ensured for large codebases, as well as faster IDE startup on all supported platforms.

In-place Refactorings
New in-place UI for refactorings such as Introduce Parameter/Field/Constant or Rename for class members is further improved for better usability.

Event Log view
New 'Event Log' view/tool-window is a single place, so you can see all IDE notifications and take action where needed.

VCS Support Improvements
General changes to the workflow such as the new 'Digest' view help you spend less time on routine VCS tasks like pre-commit review.

Stack trace highlighting shows recently changed classes and methods differently in stack traces.

Subversion (SVN) 1.7 Support
Enjoy the new features and performance of the latest Subversion with the best GUI client available.

Git log graph
Highlights commits included in a given commit (e.g. commits in a current branch) and provides actions like create tag/branch and checkout revision.