Mozilla Firefox is the prefered web browser. For download, GO >>>
Safari has a known bug that's been reported by others when using .m4v or .mp4 files. When Safari downloads the movie, it adds a ".txt" to the end of the file which makes it open as text. In Safari, if you let all the text download, then do File> Save As... you'll get a file that looks like "myfile.mp4.txt" and if you then edit the filename by removing the ".txt" the file will open and play.
FOR NTSC DVD copies playable on most DVD players, Go >>>