I'm going to write a series of articles about photo archiving in the digital age. I'm at an interesting position to talk about these issues. I am professionally a programmer with more than a passing familiarity with imaging algorithms as well as a photographer who has displayed his work in art galleries. My wife is in the process of finishing up her masters degree in Library and Information science and has a degree in History...
We tend to assume that our file formats will be with us forever, often times because many of the commonly seen file formats have been able to stick around for a while. You can still download GIF images that people used to advertise their dial-up BBS systems in the eighties and nineties before everybody was on the Internet.
People like to argue about the various archival value of various treatments, with an eye towards being able to know that if you use a specific combination of products, you'll be able to store your images for years to come.