.3MM File Extension
File Type3D Movie Maker Movie Project
What is a 3MM file?
Movie or animation created with 3D Movie Maker (3DMM) for Windows; includes a 3D scene with three-dimensional characters and objects; may also contain music, sound effects, speech, and special effects.
3MM files are also created by Microsoft's Nickelodeon 3D Movie Maker, which is based on the original 3DMM program.
NOTE: The 3D Movie Maker software has been discontinued.