The open-source EPUB e-book format is great for sharing books between different readers and making life easier on readers generally--but Amazon's Kindle, the big player, doesn't support it. Fortunately, there's a free, easy workaround: Calibre, an e-book management and conversion tool that lets you quickly port your EPUB books over to your Kindle.
If you use an e-reader, it's probably a Kindle, which means it can be a pain to use open-source e-book formats like EPUB. Calibre is a free, open-source e-book manager that lets users convert EPUB files to Kindle-readable MOBI files. Here's how to use it:
Of course, you can use Calibre to convert other e-book files as well. It's a powerful program that can really help folks who have multiple readers or who want to explore new formats.