Plucker is an Open Source free mobile and desktop e-book reader application with its own associated file format and software to automatically generate Plucker files from text, PDF, HTML, or other document format files, web sites or RSS feeds. The format is public and well-documented. Free readers are available for all kinds of desktop computers and many PDAs. PDB is a container format for record databases in Palm OS, Garnet OS and Access Linux Platform. Its structure is similar to PRC resource databases. The PalmDOC eBook format is a special version of the PDB format.
The digital book format originally used by Sony Corporation. It is a proprietary format, but some reader software for general-purpose computers, particularly under Linux (for example, calibre's internal viewer), have the capability to read it. The LRX file extension represents a DRM encrypted eBook. More recently, Sony has converted its books from BBeB to EPUB and is now issuing new titles in EPUB.