eZ Publish 5.1 is our most Scalable, most Stable and most Feature Rich eZ Publish 5.x version & eZ Publish version to date. Either if you intend to start using the 5.x API & Symfony stack or if you plan to use legacy and pure 4.x functionality, this is our recommend LTS release.
Just like 5.0, 5.1 consists of a “Dual-kernel”. On the left side you’ll see the legacy stack, an enhanced and stabilized version of the 4.x kernel. On the right side is the 5.x stack, with the arrows indicating some highlighted improvements made since 5.0.
This release brings the missing DFS clustering support in 5.x kernel allowing REST/Public API to be used in combination with clustered installation when dealing with binary files. [ PR, Doc ]
This feature enhances performance and clustering scalability by sitting between the API and the database storage engine and in default setup cache everything but search queries lowering load of backend considerably. [ PR, Doc ]
One of the steps done in this release that makes it possible to use 5.x stack fully for content rendering with standard fieldtypes without having to use legacy fallback as was the case in 5.0. [ PR, Doc ]
Twig Helper (ezpublish & ezpublish.legacy global variable) [PR, Doc]
Symfony Locale integration [PR, Doc]
Multisite with single content repository [PR, Doc]
GraphicsMagick support [PR, Doc]
Add option to allow Twig template to override rendering of legacy requests [PR1]
REST support for session authentication with CSRF token support [PR1, PR2, Specifications, Doc]
+ hundreds small/medium improvements & bug fixes in Public API, REST API, legacy and Demo bundle, see full change-log below.
With 5.1 out the door, our focus will shift more towards new 5.x based user interfaces while also improving the 5.x stack further, in no particular order:
HTTP cache for logged in users, detailed performance tracking, use Symfony 2.3 Proxy services, further profile & improve kernel
Symfony based login, full Bundle based permission integration for easier re-use in custom Bundles, ..
Future improved database handler and File storage to cross the 1 million content object soft barrier
New stack configuration, improved database and file storage that can scale across servers and datacenters, Async event handling with background daemon
Solr support, REST Oauth support (Symfony Bundle), WorkFlow, Subscription/Notification, Import/Export
Front end editing, UGC, language switcher, AdminBundle, EditorialBundle & Setup functionality
Tags, Page (ezflow) write support, Matrix, Identifier, XmlText html5 (editing and REST), Improved Media/Binary field types for cloud storage/CDN needs
|Extensibility||Criterion, SignalSlots, REST server, Limitations, code generation, ..||5.2/5.future|
Content (Search, ..), Comments (using content model), InfoCollector (using Symfony Forms), RSS, Staging, tip a friend, Rating
For technical info on feature naming and comparison between 5.x and 4.x, see this community maintained Google spreadsheet.