The air file extension is related to the M.U.G.E.N video gaming engine. The *.air file stores animation data.
AIR file extension - M.U.G.E.N animation file
What is air file? How to open air files?
File type specification:
The air file extension is associated with the M.U.G.E.N (also known as MUGEN) a video gaming engine used to visualize 2D fighting games available for PC and Mac.
The *.air file stores animation data.
The M.U.G.E.N. is obsolete product.