Calibre is a free and open source e-book library management application developed by users of e-books for users of e-books.
Now more and more fans reading books on portable mobile devices, which have already been set. E-books come about in 4312 formats. But for smart phones, mobile phones and other portable devices require their own formats and different too. Today, these formats: AZW Amazon, MOBI MobiPocket, LIT Microsoft, Palm PNPd eReader, BBeB Sony, Epub, etc. Here, you will help the program Calibre

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.
* Calibre can sort the books in your library by: Title, Author, Date added, Date published, Size, Rating, Series, etc.
* In addition, it supports extra searchable metadata:
* o Tags: A flexible system for categorizing your collection however you like
* o Comments: A long form entry that you can use for book description, notes, reviews, etc.
* You can easily search your book collection for a particular book. calibre supports searching any and all of the fields mentioned above. You can construct advanced search queries by clicking the helpful "Advanced search" button to the left of the search bar.
* You can export arbitrary subsets of your collection to your hard disk arranged in a fully customizable folder structure.
* Finally, calibre will even go out onto the internet to find book metadata based on existing title/author or ISBN information. It can download various types of metadata and covers for your books, automatically. The metadata system is written using plugins so that different types of metadata sources can be supported in the future.

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. The full list of formats can be found here.
Input Formats: CBZ, CBR, CBC, CHM, DJVU, EPUB, FB2, HTML, HTMLZ, LIT, LRF, MOBI, ODT, PDF, PRC, PDB, PML, RB, RTF, SNB, TCR, TXT, TXTZ
Output Formats: AZW3, EPUB, FB2, OEB, LIT, LRF, MOBI, HTMLZ, PDB, PML, RB, PDF, RTF, SNB, TCR, TXT, TXTZ
* The conversion engine has lots of powerful features. It can rescale all font sizes, ensuring the output e-book is readable no matter what font sizes the input document uses. It can automatically detect/create book structure, like chapters and Table of Contents. It can insert the book metadata into a "Book Jacket" at the start of the book.

Syncing to e-book reader devices
* Calibre has a modular device driver design that makes adding support for different e-reader devices easy. At the moment, it has support for a large number of devices, the complete list of which is here.
* Syncing supports updating metadata on the device from metadata in the library and creation of collections on the device based on the tags defined in the library.
* If a book has more than one format available, calibre automatically chooses the best format when uploading to the device. If none of the formats is suitable, calibre will automatically convert the e-book to a format suitable for the device before sending it.

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. Examples of supported news sites include: The New York Times, The Wall Street Journal, The Economist, Time, Newsweek, The Guardian, ESPN, and many, many more…

Calibre has over three hundred news sources and the news system is plugin based, allowing users to easily create and contribute new sources to calibre. As a result the collection of news sources keeps on growing!

Upgrading
If you want to upgrade a previous version of calibre portable, download the latest version of the installer from here and run it, choosing the location of your previous Calibre Portable install. The installer will automatically update Calibre Portable.

Release: 0.9.21 [01 Mar, 2013]
- New Features
* Content server: When browsing random books, add a button to the book page to get another random book.
* Kobo driver: Update cover uploading for Kobo firmware 2.3.1 and later.
* Add a tweak under Preferences->Tweaks to try to recoginze numbers inside text fields like title when sorting. This will cause Book 2 to sort before Book 100. However, it is slower and can have trouble when the text starts with a number. If you want numeric sorting you should use the series field for it.
* Get Books: Update the Amazon and Foyles store plugins
* Add a setting in Preferences->Tweaks that controls the sorting of the Copy to Library and Quick Switch menus. If the number of libraries is larger than the set value, the lists are sorted alphabetically instead of by frequency of use.
* Driver for Iriver Story EB12.
* Edit metadata dialog: When pasting in copied text into the comments area, you can now choose to discard all formatting. Right click on the comments area and select 'Paste and Match style' which will paste the copied text as plain text formatted in the current style.
* Book polishing: Make updating cover a separate option, so you can now update metadata without updating the cover.
* Linux build: Install zsh completion for the calibre command line utilities
- Bug Fixes
* Conversion: Do not rescale fonts sizes/adjust line heights for text based drop caps defined using a separate tag (drop caps defined using :first-letter were already handled correctly)
* E-book viewer: Fix clicking links going to slightly incorrect locations in some books.
* E-book viewer: Fix rendering of pages for right-to-left text in paged mode is reversed.
* E-book viewer: Fix bug in rendering prefixed svg tags in the cover pages of some EPUB files.
* PDF Output: Do not error out when embedding a font that Сalibre cannot subset, instead embed the full font
* Book polishing: Fix bug that caused the ORIGINAL_EPUB format to be replaced by the EPUB format when polishing a book with both ORIGINA_EPUB and EPUB
* Polishing books: Ignore unsupported fonts instead of erroring out on them.
* Make bulk edit of custom columns respect the "apply changes" checkbox even if the value to set has not changed
- New news sources: Financial Times (US subscription version) and Nezavisne Novine by Darko Miletic, Geopolityka by chemik111, Democracy Journal by David Nye, HNOnline by Ladislav Lencucha, Various Colombian news sources by Ismael Mejia
- Improved news sources: Science News, Die Zeit (subscription version)