The Kindle DX demonstrates that it is possible to licence Adobe Digital Editions but not use its DRM capability. However, we don't know if Amazon had to negotiate a special deal, or if they have a standard licence from Adobe. If this is allowed by the standard licence, Bookeen could provide DRMed MOBI and DRM-free PDF/ePub via Adobe Digital Editions.
I doubt that it is similarly possible, under its licence, to use MobiPocket's Reader DRM-free with DRMed ePubs.
|