To mark the 20th anniversary of Wolfenstein 3D, Bethesda released a free-to-play browser version of the game. Wolfenstein 3D is playable at: wolfenstein.bethsoft.com or on facebook.com/wolfenstein.
A Bethesda podcast video featuring John Carmack, the tech genius of id Software, shares his insights into the creation and development of Wolfenstein 3D while playing the game. Also Wolfenstein 3D Classic Platinum will be available on iPhone, iPad, iPod Touch free for a limited time. Check out: http://itunes.apple.com/us/app/wolfenstein-3d-classic-platinum/id309470478?mt=8