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.
Unity - The multiplatform game creation tools for everyone.
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.
Godot Engine - Feature-packed 2D and 3D open source game engine.
IntelliJ IDEA - Capable and Ergonomic IDE for JVM
Blender - Blender is the open source, cross platform suite of tools for 3D creation.