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 Book: Add auto-completion for links.
• Edit Book Function mode: Add builtin functions to change case of text, ignoring HTML tags in the matched text
• Edit Book - Check Book: Allow auto-fixing of file not in spine errors
• Driver for Papyre 624 ml
• Conversion: Convert images encoded as data URIs in the input document into normal images, as some ebook reader software cannot handle data URIs.

• AZW3 Input: Handle AZW3 files that contain Amazon specific CSS media queries.
• Fix regression that broke the markdown-calibre command
• Edit Book - Show what changed: Fix scrollbar sometimes not visible if the differences contain a few, very long lines. Also fix the line numbers being partially obscured on some systems (depending on the font used).
• Edit Book: Fix a regression that caused the Home key to not move to the start of the line on lines containing un-indented tags
• Get Books: Update the Amazon (US) plugin for website changes.
• MOBI Input: Fix incorrect conversion of MOBI files that wrap their content inside anchor tags.