New in calibre 3.0

Welcome back, calibre users. It has been almost three years since calibre 2.0. In that time lots has happened. The biggest new feature, which was in development for almost that entire period, is a completely re-written calibre Content server.

The Content server allows you to wirelessly browse your calibre books on any modern phone/tablet and even read the books right in your phone browser. The books are stored in off-line storage on the phone so you do not have to keep calibre running or have an always on internet connection to read the books.

The new Content server You can start the Content server by clicking the Connect/share button in calibre. Then just open up a browser and type http://localhost:8080 in the address bar. You will see a list of calibre libraries. Click on one and browse the books. Click on a book and you will have the option to read or download it. To learn more about using the server to read on your devices, see the User Manual.

Support for High Resolution (Retina) screens A much requested feature. As of calibre 3, calibre now natively supports high resolution (Retina) screens. It should auto-detect when it is started up on such a screen and adjust itself accordingly. It can be controlled via Preferences → Look & feel → Adjust for high resolution screens .

Support for icon themes and a new default icon set calibre now has support for installing different icon themes ( Preferences → Look & feel → Icon theme ). There are many different icon themes to suit different tastes. In addition, to celebrate calibre's tenth birthday, which was in October, 2016, the default calibre icons have been changed. Never, fear if you prefer the old icons they are also available, as an icon theme.

Conversion to Microsoft Word (DOCX) calibre can now convert all the book formats it supports to Microsoft Word (DOCX) files. Alongside the support for conversion from Word, you can now go back and forth between Word documents and e-book formats to your hearts desire.

Backwards incompatibilities There are a few minor backwards incompatibilities to be aware of in calibre 3. The Content server was completely re-written. While we have tried hard to make sure the functionality used by third party programs that connect to calibre remains compatible, there is likely to be some breakage. Also, no changes you have made to any server options will be preserved. For example, if you changed the port from the default of 8080, it will be reset to 8080. You will have to redo the configuration. Because the Content server can now make changes to calibre libraries, you can no longer run any of calibredb.exe, calibre-server.exe or calibre.exe together, as they are all capable of modifying calibre data. Instead of running calibre.exe and calibre-server.exe, use the embedded server inside the main calibre program. calibredb.exe can now connect directly to a running calibre server (either calibre-server.exe or the server running inside calibre). See the User Manual for details on how to do that. On Linux calibre can no longer use the system Qt theme/style plugins as they cause hangs/crashes on some systems. This means calibre might look a little different from other applications on your system. You can force the use of the system theme by setting the environment variable CALIBRE_USE_SYSTEM_THEME , but do so at your own risk.



This is an appropriate time to throw out a big thank you to the calibre community who have contributed selflessly of their energy and enthusiasm — without which many of the features above would never have seen the light of day.

Note that some of these features were actually introduced during the lifetime of the 2.x series. This document describes new features as compared to 2.0

See what was new in previous major calibre releases: 2.0, 1.0, 0.9, 0.8, 0.7.