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.

• Edit metadata dialog: Facilitate editing the authors for books that have a large number of authors, by using a dedicated 'Edit authors' tool, which you can launch by right clicking the authors in the edit metadata dialog and selecting 'Edit authors'.
• Conversion: Fix specifying shorthand properties in filter css not working. Now all shorthand properties automatically filter out all the properties they are shorthand for.
• Kobo driver: support new firmware version 3.0.1
• Wireless device driver: Cache metadata on a per device basis.

• Metadata download: Update code to get covers via google image search to handle changes to the google website.
• Searching: When searching for identifiers, fix searching for values that contain colons not working. Also fix escaped parentheses not being parsed correctly.
• Match books on device: Fix parentheses in book titles not being escaped when searching for matches.
• Match books on device: Fix thumbnail in device metadata cache not being updated when matching books.
• File open dialogs; If the previously used initial directory, no longer exists, use a directory one level up.
• EPUB Output: Strip -- from inside comments, as some ebook reading apps cannot handle them.
• Fix a regression in the previous release that broke the Kobo third party plugins
• Fix QuickView windows not staying on top on some linux systems
• Fixes for website changes for various Get Books Polish language stores
• Metadata download dialog: Fix current cover not copyable to clipboard
• Fix an incorrect translation of the language 'Polish'