[kovidgoyal]

Hi all,

After almost three years of on-and-off development, calibre 3.0 is now ready for beta testing!

Please run the beta as you would normal calibre and report any problems you encounter in this thread. I have been personally using the beta calibre on linux as my normal calibre for several months now with no problems. There are no changes to the database/conversion/viewing/editing/user interface code so those should all work just as before. That said, always be safe by backing up your data before trying out the beta.

Thank you for your help in making calibre 3 possible!


The major new features are:

Spoiler:

1. All new Content server.
   
   • You can now read books directly in a web browser, even when there is no internet connection. This means you no longer need to use an app on your phone/tablet to read books. Instead you can directly connect to the calibre server and read books in the browser itself. The books are stored in offline storage so you can read even when the network is not available.
     
   • The server can show multiple calibre libraries
     
   • The server supports multiple user accounts. And you can control which libraries each user can access.
     
   • The server can now make changes to your calibre libraries (adding books, editing metadta, etc.). Currently this feature can only be accessed using the calibredb command line tool. A web user interface for it will be added in the future.
     
   • The server is very new and will have many missing features. These will be added over the course of normal calibre development after calibre 3. Feel free to request new features as part of your beta feedback. A list of features I intend to add in the future is here: https://github.com/kovidgoyal/calibr...e/srv/TODO.rst
2. High DPI (Retina) monitor support
   
   This is automatic if you have a High DPI monitor, calibre's interface should get scaled appropriately. You can turn it off via Preferences->Look & Feel->Adjust for high resolution screens

Backwards incompatibility:

Spoiler:

• The Content server was completely re-written. While I have tried hard to make sure the APIs used by third party programs that connect to calibre remain compatible, there is likely to be some breakage. Also, no changes you 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 calibredb.exe, calibre-server.exe, 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 https://github.com/kovidgoyal/calibr.../custom.py#L99 for details on how to do that.
  
• On linux calibre can no longer uses 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.
  

How to install the beta

Spoiler:

Betas for all platforms are available here: https://download.calibre-ebook.com/betas/

They have version numbers starting with 2.99. You can install them just as you would a normal calibre. If something goes wrong, simply un-install and go back to using the current calibre release.

On Windows, you can also use the calibre portable beta to test things in an isolated way.

On macOS you can simply install calibre.app somewhere other than /Applications and run it separately from your main calibre install.

On Linux you install the beta by un-tarring the tarball into some empty directory, for example, in a terminal:

mkdir calibre-beta && tar xvf /path/to/downloaded/tarball.tar.xz -C calibre-beta

and then run the beta as:

calibre-beta/calibre

Known issues

Spoiler:

• The new Content server is a very large piece of software written from scratch over several years (~ 20,000 lines of code). As such, it is bound to have problems, especially given the wild diversity of browsers out there. I have tested it on Chrome and Firefox and I know that it does not work well with Microsoft browsers (Internet Explorer and Edge) which are missing features it needs. But, there are many other browsers out there for which I dont have the resources to test, most prominently, Safari on macOS/iOS.
  
• On windows, calibre is now built with Visual Studio 2015 (upgraded from Visual Studio 2008). While this should cause no problems, there might be issues, especially on older windows, like Vista.