- A completely re-written Content server with support for reading books in-browser on your phone/tablet. Also works in offline mode.
- Support for high resolution (Retina screens)
- A new splash screen to celebrate the release of calibre 3
- Minor tweaking of the main user interface to emphasize the core features
- 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.