At last month's QuakeCon convention in Dallas, id Software chief technology officer John Carmack showed off an iPhone version of Rage using the id Tech 5 engine. Not to be outdone, Epic Games today used Apple's annual music-themed press conference to unveil its own Unreal Engine 3 technology running on the computer maker's iOS line of handheld media players.

　　Epic Citadel will let users explore a world "inspired by" Chair's Project Sword. During the event, Epic Games president Mike Capps and Chair Entertainment creative director Donald Mustard showed off Project Sword (tentative title), the first Unreal Engine 3 game for iOS devices. Developed by Chair and due out later this year, Project Sword is a mix of action, adventure, and role-playing game elements in a sword-swinging medieval setting. Acquired by Epic in 2008, Chair is best known as the developer behind the Xbox Live Arcade games Shadow Complex and Undertow.

　　While Project Sword won't be available for some time, Epic is releasing a free app on the iTunes Store that will show off Unreal Engine 3's performance on the iPhone, iPad, and iPod Touch platforms. That app, Epic Citadel, allows players to explore a castle in the game's setting and is intended in part to show off what developers can do using Unreal Engine 3 for Apple's devices. Epic noted the tech demo was created by "a small team" of programmers, artists, and testers in eight weeks.