Books
Iron Man is so far the only non-X Men related character to appear in the X-Men Dimensions series. He appears in X-Men Dimensions 3, telling Scarlet Witch that it is okay to go and help the X-Men during an attack involving the Brotherhood. Even though he is the only non-X Men related character to appear, he does crack a joke about Thor, and the Avengers have been referenced frequently since the series second installment.
The Iron Man armor is prominently featured in the book Inventing Iron Man: The Possibility of Creating a Human Machine, written by E. Paul Zehr, which explores the hard science fiction aspects of Iron Man and the possibility of building a Iron Man-like armor.
Read more about this topic: Iron Man In Other Media