Rock-hard (and indeed contains various rocks such as gravel), never goes stale, and is terribly sustaining. A traveller can go for miles, just knowing there’s dwarf bread in their pack. A traveller can think of just about anything to eat rather than dwarf bread including their own foot and even pumpkins (see Witches Abroad).
Various forms of dwarf bread can be used as weapons, e.g. battle muffins and drop scones. Fine specimens of dwarf bread can be found in the Dwarf Bread Museum, Whirligig Alley, Ankh-Morpork, open to the public whenever volunteers have time (Feet of Clay).
This comment section is getting way too credible
A lot of (bigger) bookstores also sell ebooks on their websites. There it usually depends on the publisher if they have DRM or not, so just look around.
It was all a conspiracy by big CGI
pds: ich mit 160 auf der Autobahn