There's a lot of third-party stuff for these in Windows, including in commercial software like Photoshop. So the formats can't be THAT secret.
Anyway, all of the links above, as well as the ones I've found on my own Googling, are really just works in progress and kitrchen sink experiments. They're full of all kinds of caveats, and lists of stuff that's not fully supported, and pleas for more information and discoveries about the underlying data format, etc.
Raw format is not used by casual snapshooters; it's for advanced photographers and professionals. If I'm paying for a model, and a hair stylist and a make-up artist, I can't afford to entrust the images I get to code that's still "stuggling to do color handling corectly" (quoting one of the above links.)
This illustrates why Linux is still struggling to escape the Geek Ghetto. Both Linux and Windows are engaged in a conspiracy to lower people's expectations. Windows lowers their expectations that computers shouldn't crash all the time ("sure XP crashes several times a day, but I just save my files a lot and reboot! What the big deal?") Linux lowers their expectations that applications should actually be fully functional and professional quality ("Sure it only does black and white today but I'm sure by the next release he'll support color and meanwhile, in between clients, I'm teaching myself C++ and vi so I can write my own ICM plugins for it...")