eZ Publish Platform 5.3 is a LTS (Long term supported) release (see http://support.ez.no/Public/Service-Life for supported period), it mostly offers a continuous improvement of the "Platform stack" (previously referred to as "New Stack", "Symfony stack" or "6.x stack") introduced with eZ Publish Platform 5 in terms of features, usability and performance.
It serves the needs for both a future proofed websites on top of the upcoming "eZ Platform" stack, and as a stable foundation for upgrade needs for existing legacy (4.x) sites with support for the next 3+2 years.
It will also be easily upgradable to 5.4 which will have same legacy kernel+extensions as 5.3, is supported for the length of the 5.3 support period and provide additional features in the "eZ Platform" stack for those in need for near eZ Platform 1.0 functionality, but on 5.x with it's legacy (4.x) compatibility at the same time.
5.3 introduces several new features which makes it easier to use, faster to develop on and also continues to improve performance.
eZ Publish 5.3 now uses Doctrine DBAL instead of Zeta Components Database, this allows users to reuse database connection and settings with other pure Symfony2 bundles which uses Doctrine ORM (default choice in Symfony2 documentation and code generators).
New login / logout functionality that uses Symfony's authentication system, this enables any kind of login handler or SSO handler made for Symfony to also work with eZ Publish 5., including handlers for LDAP.
Allows use of existing legacy SSO handlers with the new user login system in 5.3 which is powered by Symfony.
With 5.3 your content previewing needs, also from the current legacy based admin interface will run on the new "eZ Platform" stack, avoiding that you need to also create all templates in legacy to be able to preview correctly.
Developer feature known from legacy which allows you to see which templates are used on a page, how many times and how much time they spend being executed.
The language switcher is built on the Symfony stack and is improved for a simpler usage.
Tree based "fetches" are now allowed be performed with the new Location Search API, allowing generation of tree structures much more easily by returning the location instead of content, as done by existing Content Search API, and by applying any location filters on the specific location instead of any of the locations of a Content object.
HTTP Cache aware, CORS support and support for OPTIONS method.
Search API is now able to search for content with geolocation making it possible to do geolocation range searches and sorting by distance from a point; on Demo site this is shown using a restaurants-close-to-you page.
Documentation : 2. Browsing, finding, viewing#2.Browsing,finding,viewing-Search
With this new feature mixing legacy and "eZ Platform" needs has become a whole lot easier. Easily said it allows you to place legacy extensions within a Bundle structure and eZ Publish 5.3+ will make sure it is injected into legacy kernel.
Example use case: CommentsBundle with a light admin tab in legacy allowing you to moderate comments.
Not to be mixed with the Web Debug Toolbar provided by Symfony and extended by eZ Publish, this feature is about allowing "ezwt" (Website Toolbar) extension to also work in DemoBundle to provide the front-end editing functionality that you know from 4.x.
Solr 4.7.0 support in ezfind allows for use of new functionality provided by Solr 4.x such as Solr Cloud allowing Solr to be scaled out over several servers, it also provides improved performance for indexing and new options like soft commit to control this.
Taking advantage of the MapLocation feature a new feature is exposed in the demo showing how to implement listing and map views of content using the maplocation field.
For 5.3 we want to reach out a special thank you to those that have contributed to this release, especially the brave few who have helped out on the "eZ Platform stack":
In addition ezpublish-legacy is still receiving a lot of pull requests, the also brave contributions to this part of the release can be found here.
For the full 5.3 changelog please refer to the 5.3 Changelog dedicated page.
The complete list of know issues is available in the 5.3 Known issues page.