Late last year, the developer who created popular indie game Canabalt released the game's source code under an MIT open source license. This license lets other developers use the underlying game engine to power their own games for either private or commercial distribution. While the underlying engine is free to use, the Canabalt developer clearly states other developers cannot "distribute or redistribute our game code, art or sounds."
Unfortunately, PLD Soft may have violated this open source license by taking the source code, repackaging it with minimal changes and submitting it to the App Store as an app called Free Running. Apple approved this Canabalt clone, and it is now available for free.
While it may prevent the entry of harmful and poorly written applications into the App Store, Apple's approval process is not perfect. Just last week, a Mario clone made its way into the App Store, and now we see the debut of a Canabalt clone. The Mario clone had a limited lifespan and was pulled promptly from the App Store, we will wait and see if Free Running meets the same fate.