CompuServe Messages

You've touched upon the cardinal point with your "alphabet" example: since you cannot copyright languages, there must be some other form of protection. And there is: the patent. Patents have been granted for a number of file formats, computer programming languages, and transmission protocols. All of these are used to describe various ideas, all of which can be copyrighted themselves. As long as the language is not patented, you are free to use it however you may. Patents protect processes and methods, and a language is just a method of expressing an idea. Since the life span of a lot of software is just a few years (at most!), most companies will not patent file formats because of the time and money involved. They normally will keep them internal unless it's politic to make them public (ie IFF and WK1 to name a few), but an enterprising programmer can legally decode and use any non-patented file format. That's why so many software companies have employee non-disclosure contracts… My understanding of the Kodak Photo-CD format is that it is not patented nor do they have an application in at the Patent Office. Makes the format fair game in the eyes of the law. If they do patent the format it'll be time to get out the license-fee checkbook.