There is only one file type that uses the .KMCOBJ extension:
Kinemac Sprite Object
3D object that can be imported into a Kinemac animation; can be dragged onto the Stage window after opening or creating a .KMC file; may contain references to images or video clips that have been applied to the sprite.
NOTE: By default, KMCOBJ files are not saved along with their referenced files. In order to save a sprite with the associated image and movie textures, hold down the Option key and drag the KMCOBJ file to the Finder.
Updated: December 18, 2008