Originally, the Mobipocket format was intended for use with Palm Pilots as well as other personal digital assistants. The software was then purchased by Amazon.com in 2005 after Amazon decided to build what is now known as the Amazon Kindle. This format allows Amazon to lock each device with what's called digital rights management. This means that when a user downloads a book onto their Kindle, it's locked to that device only. The book cannot be traded or loaned without Amazon's permission.
This ebook format is essentially a base for other formats to be built off of. With a magnitude of standards as well as solid formatting, the ePub can be shaped into as many shapes and sizes as the publisher would like. While the ePub hasn't caught up with formats such as Amazon's Kindle or Sony's Broadband eBook, it has potential to grow even bigger. These files can be read by the ereader application which can be used by devices such as the iPad, mobile phones as well as on computers using either the Windows or Mac platforms.
Founded by Sony, the Broadband eBook format is used by the Sony Reader. Unfortunately, this format is limited to devices sold by Sony alone, so there isn't much room to grow when compared to other formats. Because of this, Sony announced in 2009 that they would be discontinuing the format and using ePub in place of it. However, no changes in the Sony Reader's format have been made at this time.
Portable document formats or PDFs are one of the most common electronic document formats. Not just limited to ebooks, PDF files have been used by businesses and individuals to share ideas, contracts as well as guidelines. The PDF format can be printed from just about any printer and can be read by users who have downloaded PDF software such as Adobe Reader. However, the main issue PDF formats have in the common e-publishing world is that they cannot be resized to fit smaller devices. Due to this small setback, the file must be zoomed into on smaller devices in order for the user to read them.