BookFusion!

Calibre is a free and open source e-book library management application made by users, for users. Many languages, designed around the concept of the logical book, i.e., a single entry in your library that may correspond to actual e-book files in several formats.

FBReader is an e-book reader for various platforms.

Amazon Kindle software lets you read ebooks on your Kindle, iPhone, iPad, PC, Mac, BlackBerry, and Android-based device. You can discover and read over 630,000 books in the Kindle Store, including the latest bestsellers and new releases.

Google Play Books lets you search, preview, and buy millions of books using Google Book Search. Books in the public domain and certain copyrighted books can be read and downloaded in their entirety for free. You can buy ebooks for reading on your computer, Apple device, Android device, Nook, or Sony eReader in the Google ebookstore. All purchased eBooks are backed up online, and your page positions are automatically synced between devices.

Sigil is a multi-platform WYSIWYG ebook editor. It is designed to edit books in ePub format.

Innovative book reader with powerful controls & full functions:

Aldiko is an e-book reader application for the Android operating system. It supports the EPUB industry standard format for digital publications and incorporates facilities for browsing online catalogs on thousands of books (including thousands of free public domain work) and downloading them directly into the users personal library. The application features a bookshelf-like user interface that lets user navigate their collection of eBooks. It also provides a customizable reading experience through configurable font and background color, font size and type, margin size, display brightness, page turn mode, etc. Additionally, the application allows users to import their own books to read them on the go. »

EPUBReader is a Firefox addon which lets you read ePub-files just in the browser. You don't need to install additional software!

A fork of the last GPL version of EBookDroid. Supports the following formats:

Ebook Library management and reader. Supports DRM protected PDF and EPUB files.

K2pdfopt (Kindle 2 PDF Optimizer) is a stand-alone program which optimizes the format of PDF (or DJVU) files for viewing on small (e.g. 6-inch) mobile reader and smartphone screens such as the Kindle's.

Read, search, make notes & highlights in PDF (Adobe DRM), EPUB (Adobe DRM), DjVu, TXT, FB2, FB2.zip book formats. Enjoy a unique, fast and user-friendly interface that was designed to provide the most convenient set of options for you to fully enjoy reading a book.PocketBook reader allows you to customize your reading experience by adjusting text size, layouts, colors and many other options.

Calibre Web is a web app providing a clean interface for browsing, reading and downloading eBooks using an existing Calibre database.