"RAW data is usually stored in the DNG file format, which stands for Digital Negative. Some camera makers have their own formats, but those companies are jerks."

I disagree with the second part of this quote. The major players (Sony, Canon, Nikon) have their own file formats which reflect the choices their engineers made in deciding how to record the raw sensor information at the time of the exposure. Theoretically you can make the case that one of them did it better than the others but since the applications photographers use to process RAW images are given the ability to read these RAW formats they aren't being jerks just for wanting to express their engineering genius in their own way. If, for example, Nikon REFUSED to give Adobe and others the ability to decode their raw NEF files, insisting you have to buy a piece of Nikon software in order to view and transform the raw images from your camera, then I would agree they are jerks. But just because a camera maker's engineers decided that (for reasons I don't know) the open DNG format won't deliver the best quality to their customers doesn't make them jerks.

Otherwise this is a pretty good article, even if it's little more than an educational promotion for Halide's camera app.