Originally Posted by Fat Abe
Look for ereader format, which seems to be a code-name for Adobe pdf (?).
It isn't. eReader format is a format originally designed by Peanut Press, an early ebook publisher targeting Palm OS PDAs. It uses a markup language called Palm Markup Language, which supports color, embedded images, hyperlinks, text attributes, and (depending upon the platform) custom fonts.
Palm bought them and made them the Palm Digital Media Division, and distributed a freeware version of the reader called Palm Reader with Palm OS PDAs. They later sold the division to Motricity, an ouffit vending B2B mobile content solutions, who renamed it eReader. Motricty allowed it to languish, and eventually sold it to Fictionwise, who were in turn acquired by Barnes and Noble. eReader has freeware viewers for an assortment of platforms, and the Barnes and Noble nook dedicated reader supports PML formatted books as a legacy format, in addition to the primary ePub format.
You can get available clients for eReader documents here:
A freeware Windows application for creating eReader documents from handwritten PML source is here:
A payware WYSIWYG GUI program for creating eReader documents is here:
Information about PML is here:
And you can still buy commercial eReader titles: