I've been doing some reading on RAW and DNG (Digital Negative) image file formats and thought I wold share my findings. It appears that a majority of camera manufacturers have there own proprietary specification of the RAW format. While this sounds fairly innocuous, we need to keep in mind that there is no guarantee that these individual specifications will be supported in the future which means that all of your archived work could become non-accessible. In true open-source form, the DNG format was devised by Adobe. This is an open standard specification and is therefor not subject to proprietary copyright restrictions which means that anyone can develop software based on these specifications. Adobe provides the free Adobe DNG Converter which easily translates raw files from many of today's popular cameras.
Hope you find this of use.