is a format used in the MobiPocket Reader software on desktop and mobile platforms. Books in this format can have .prc and .mobi file extensions. MOBI was originally based on the PalmDOC format; adding HTML tags made it possible to create a high-compression version which compresses data to a high degree. There are a number of formatting restrictions – the text cannot be indented, and inserted tables and images cannot be formatted.
is an e-book format created for Amazon’s Kindle8. This format supports the CSS3 pop-up text system and HTML5 as well as built-in fonts; moreover, it possesses powerful document-formatting capabilities. It contains a function of independently activated DRM protection. AZW3 books can be created with KindleGen, a free software program from Amazon.