Java Developer Tools
Eclipse
Eclipse is an open source community whose projects are focused on building an open development platform comprised of extensible frameworks, tools and runtimes for building, deploying and managing software across the lifecycle. A large and vibrant ecosystem of major technology vendors, innovative start-ups, universities, research institutions and individuals extend, complement and support the Eclipse platform.
NetBeans
All the tools software developers need to create cross-platform Java desktop, enterprise and web applications. Runs on Windows, Linux, MacOS, as well as Solaris. It is easy to install and use, works right out of the box -- and it is open-source and free!
Oracle JDeveloper
Oracle JDeveloper is a free integrated development environment with end-to-end support for modeling, developing, debugging, optimizing, and deploying Java applications and Web services.