"digiKam comes with a nifty batch utility that allows
you to convert RAW files to the DNG format. The question is, of
course, why you would want to do that. After all, digiKam can
handle RAW files without any problem, so what's the point of adding
one more step to your photographic workflow?
"As you might know, RAW is not a file format, but rather an
umbrella term that describes multiple file formats controlled by
multiple hardware manufacturers. The RAW formats themselves are
specific to digital camera manufacturers. For example, Canon
cameras store RAW files in the CR2 format, while Nikon cameras use
the NEF format. Besides being proprietary, RAW formats are often
poorly documented and encumbered by patents."