Netbeans - NetBeans IDE 7.0. Develop desktop, mobile and web applications with Java, PHP, C/C++ and more. Runs on Windows, Linux, Mac OS X and Solaris. NetBeans IDE is open-source and free.
Visual Micro - Arduino IDE for Visual Studio and Atmel Studio
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.
Visuino - Visuino is a visual programming environment that lets you write programs from Arduino circuit boards.
IntelliJ IDEA - Capable and Ergonomic IDE for JVM
ArduBlock - ArduBlock is a graphical programming language plugin specifically made for Arduino circuits and controllers.