Unity is an integrated authoring tool for creating 3D video games or other interactive content such as architectural visualizations or real-time 3D animations. Unity is similar to Director, Blender game engine, Virtools or Torque Game Builder in the sense that an integrated graphical environment is the primary method of development.
The editor runs on Windows and Mac OS X and can produce games for Windows, Mac, Wii, iPad, or iPhone platforms. It can also produce browser games that use the Unity web player plugin, supported on Mac and Windows. The web player is also used for deployment as Mac widgets. Support for Xbox 360 and PlayStation 3 have recently been added.
There are two main licenses: Unity and Unity Pro. The Pro version has additional features, like render-to-texture and postprocessing effects. The Free version also displays a splash screen (in standalone games) and a watermark (in web games).
via Unity (game engine) – en.wikipedia.org
I’m adding this to my list of things to learn. The Pro version is expensive ($1500, plus $400 for iOS or another $1500 for iOS pro or Android pro), but it looks like the free version doesn’t skimp on anything really important. I already have a lot of complementary skills, so I think I could be up and running pretty quickly here.