CompuServe Messages

You probably don't want to find, purchase and read all the actual file specifications for those formats. They're quite complicated, and you'd be better off searching for magazines that contain summaries of these technologies. Certainly most Mac and PC magazines have covered them in depth in recent years. Why are there so many formats? Some of them are promoted by private parties with vested interest in recruiting people to their platform and technology (AVI) while others are promoted by public, non-commercial entities, or some are in-between. They have different intentions, too, or at least they started out that way. For example, today you see advanced MPEG compression used in direct satellite systems, while QuickTime is actually a general database format for storing any time-dependent data, while AVI is certainly optimized for CDROM playback on PCs.