calibre is a free and open source e-book library management application developed by users of e-books for users of e-books.
It has a cornucopia of features divided into the following main categories:
- Library Management - calibre manages your e-book collection for you. It is 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.
- E-book conversion - calibre can convert from a huge number of formats to a huge number of formats. It supports all the major e-book formats.
- Syncing to e-book reader devices - calibre has a modular device driver design that makes adding support for different e-reader devices easy.
- Downloading news from the web and converting it into e-book form - calibre can automatically fetch news from websites or RSS feeds, format the news into a ebook and upload to a connected device. The ebooks include the full versions of the articles, not just the summaries.
- Comprehensive e-book viewer - calibre has a built-in ebook viewer that can display all the major ebook formats. It has full support for Table of Contents, bookmarks, CSS, a reference mode, printing, searching, copying, customizing the rendering via a user style sheet, embedded fonts, etc.
- Content server for online access to your book collection - calibre has a built-in web server that allows you to access your ebook collection using a simple browser from any computer anywhere in the world. It can also email your books and downloaded news to you automatically. It has support for mobile devices, so you can browse your collection and download books from your smartphone, Kindle, etc.