Missing in Action is a mod for registered Wolfenstein, made by David Nevin. It was released on March 10, 2002.
Released as a demo, though with no full version ever made, it features 6 levels and a number of changed graphics. No storyline is featured, though an actual World War II atmosphere can be felt in the new graphics, which features surrendering enemies and tanks.
No source code changes were made, and it is thus playable in SDL.