Version 4 of the calibre ebook library and reader is now available

Written 8 months ago by IanDorfman

Ebook lovers, rejoice! In its first major version release in 2 years, the development team behind the calibre electronic book library and reader has announced that version 4.0 is now available.

This new release includes features like a complete rewrite of the ebook viewer, PDF output, and book details functions due to changing from Qt WebKit to Qt WebEngine. This engine change is because of support for Qt WebKit development no longer being maintained. The new ebook viewer has a design that emphasis the text of any book, with no visible controls present to obfuscate the words on a page. Additionally, the ebook viewer and built-in browser viewer now share a code base, so features for both parts of calibre will be easier to develop and deploy. The official announcement post specifically references upcoming support for annotations.

Small calibre iconcalibre content servers now feature every major capability present within the main calibre UI, including the ability to edit metadata, convert books, and add/remove books and formats that the program supports. A tutorial on how to use the newly redesigned content viewer can be found as a thread on the MobileRead Forums.

The post detailing the release on the official website also notes that, due to the replacement of Qt WebKit with Qt WebEngine, certain minor incompatibilities may occur. Since the new book details manager no longer uses a full browser engine to render in order to reduce system resource use, less CSS and HTML is supported when compared to earlier versions of calibre. This means that comments made using advanced CSS and HTML styling may not properly display in 4.0. Additionally, markup for header and footer templates when converting files to PDFs has changed, with a detailed breakdown available via the calibre's official online documentation.

Version 4.0 of calibre is available now for Windows, macOS, and Linux on its official website.

Further coverage:
Official calibre website post