Calibre is a free and open-source e-book management software that allows users to manage their e-books, convert between different e-book formats, and sync e-books with various devices. It was first released in 2006 and has since become one of the most popular e-book management tools available.

One of the most notable features of Calibre is its ability to organize e-books into different categories and add tags, making it easy to search and locate specific books. It also allows users to edit the metadata of their e-books, including the title, author, and cover image, and can even download missing metadata from online sources.

Calibre also provides a powerful e-book conversion tool, allowing users to convert e-books from one format to another, such as from EPUB to MOBI, or from PDF to EPUB. This is particularly useful for those who want to read e-books on different devices that may not support the same file format.

In addition, Calibre supports a wide range of e-book readers, including Amazon Kindle, Barnes & Noble Nook, and Kobo e-readers, and can automatically sync e-books with these devices. It can also connect to online e-book stores, such as Amazon and Google Books, allowing users to browse and purchase e-books directly from within the software.

Calibre is an essential tool for anyone who reads and manages e-books. Its powerful features and easy-to-use interface make it a must-have for anyone looking to organize, convert, and sync their e-book library.

Key Features:

• Library management system to organize e-book collection
• Format conversion for compatibility with different devices
• Built-in editor to modify e-book metadata and table of contents
• E-book viewer with customization options
• Integrated web browser for downloading e-books
• Synchronization options for keeping e-book collection up-to-date across devices
• Extensible with plugins to add additional features and functionality.

New Features

• Edit metadata: In the drop down list for languages, show the five most recently used languages first.

  Closes tickets: 1594089

• Edit Book: Check Book: Add a check for missing navigation documents in EPUB 3 books
• Kobo driver: Improved configuration dialog for the Kobo Touch device driver
• Copy to Library: Do not abort the copy process if only some books fail to copy, instead report which books failed and copy the rest.

  Closes tickets: 1594100

• News download: Make all relative links (those starting with /) absolute. Useful when reading on a device that supports web browsing.
• EPUB metadata: Add an option to disable adding of cover images to EPUB files that declare no cover image in their metadata (Preferences->Plugins->Customize the Set EPUB metadata plugin)

Bug Fixes

• ToC Editor: Fix ToC detection in EPUB 3 files with only an NCX and no nav not working
• E-book viewer: In paged mode, when the window is toggled between full screen and window, repeatedly, preserve the position more accurately.

  Closes tickets: 1595307

• E-book viewer: Fix incorrect page turning when multiple pages are displayed on screen for books that wrap all their content in a single 100% height tag.

  Closes tickets: 1594657

• Fix a regression that broke scheduling a new news download in timezones west of GMT
• Edit Book: Fix undocked windows not resizable on OS X
• Fix a regression in 2.57 that broke rescaling of images to fit the output profile screen size during conversion.

  Closes tickets: 1594098