Fun thing is, there's also loads of Wolfenstein-inspired Add-Ons and TC's for Doom.
For instance, offers a ZDoom TC, exactly mimicking the original Wolfenstein 3D, yet with all of the Zdoom engine's features. Check it out too, it might possibly the next best thing: if you use FreeDoom as a base, you will have the gameplay experience of Wolf3D, in a legal construction!