This format is used for storing bitmap images. It supports many different file types and compression algorithms. One Palm bitmap file can contain multiple versions of the same images with different colors. These files are used on PALM devices.
was developed for the first mass-produced e-book reader – Rocket eBook. The format is written in Ruby. RB files are containers holding the entire content for a Rocket eBook device. It has DRM protection capability which is not used in the books published at present due to the format’s lack of popularity.