I looked into its source and it's a bit complicated for me at this stage. I learned that Alien Arena has IQM completely implemented, so I'm downloading it now. I also found evidence

It seems that I could duplicate the .dpm function or the .md3 one and add in the IQM info.
So, if no one cares to join the discussion, I'll come back with whatever I can find on this.
EDIT #1: Shouldn't be too hard. Xonotic implementation uses only 2 files for the engine side.