MSE (MediaShow Slideshow Project File)
The MSE Video file format
MSE files are used by a program called MediaShow. With this program, users can create slideshows or videos for sharing and presentation. The MSE, however, does not contain the actual slideshow. Rather, it is a project file containing a list of elements used in a slideshow, such as text, images, transition effects of said images, background music, and the like. For the slideshow to be played, the MSE project file needs to be exported as a video format such as MPG or WMV.
Technical details of MSE files
Since MSE files are project files and not actual slideshow files, they only work with the application they are created with. Even if an MSE file is shared between machines that have MediaShow installed, it is not guaranteed, that the project will work as expected. The resources used, images and music, need to be present on the computer as well.