DOWNLOAD - What a .download file is and how to open it
MP4 File: Definition, How to Open and Convert?
QuickTime MP4 with H264 Codec Compression - Use this Workflow to make a .mp4 not a .mv4 like Adobe Makes using a similar workflow - Moody College of Communication - UT Austin Wikis
Big list of sample videos for testers - standaloneinstaller.com