Calibre is an Ebook management software.

Sigil is a free, open source, multi-platform ebook editor.

OverDrive Media Console enables users to access audiobooks, eBooks, periodicals, and videos borrowed from libraries and schools.

FBReader is a free ebook reader. Main ebook formats: ePub (including main features of ePub3), Kindle azw3 (mobipocket), fb2(.zip).

EPUB is an e-book file format with the extension .epub that can be downloaded and read on devices like smartphones, tablets, computers, or e-readers.