We just published a first release candidate for the next major version 1.4 which has now been in development for quite a while. Although the new responsive Elastic skin is now functional and feature complete, it still lacks the final brush-up to make it shine. We have now finally found a volunteer to work on this and once completed, a second release candidate will follow.
For now you’re all invited to give the new 1.4 version another test run. Besides the responsive theme it comes with lots of new features and improvements since the beta release. Check the Changelog  for a complete list of changes.
Please also try customizing the Elastic skin using the _styles.less and _variables.less files and let us know what’s missing. You’ll find guidance in the README.md file inside the skin folder.
Because we don’t yet consider the Elastic theme fully complete, it’s not set to be the default theme. Adjust your config in order to enable it with
$config['skin'] = 'elastic';
This is a beta release and we recommend to test it on a separate environment.
And don’t forget to backup your data before installing it.