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.
Architecture overview as of 5.1
Just like 5.0, 5.1 consists of a “Dual-kernel”. On the left side you’ll see the legacy stack, a 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.
Highlighted 5.1 features in 5.x stack
IO Clustering support for use with legacy DFS
Persistence DB cache using Stash
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 ]
eZPage (ezflow) FieldType read-only support
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 ]
Small but big improvements in 5.x stack implemented in 5.1
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, Doc]
Thousand small and medium improvements in Public API, REST API and Demo bundle, see full change-log below.
5.1 Feature status for 5.x stack
As 5.1 (just like 5.0) contains a “Dual kernel”, this overview is to provide some guidance on when to use legacy stack, 5.x stack or both.
HTTP cache for logged in users, Profile & improve new kernel to speed up uncached execution
Missing native login, full Bundle based permission integration
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 many servers and datacenters, Async event handling with background daemon
WorkFlow, Subscription/Notification, Import/Export, REST Oauth support, Solr support w/ ezfind integration
AdminBundle, EditorialBundle, front end editing, language switcher & Setup UI
Tags, Page (ezflow) write support, Matrix, Identifier, XmlText html5 (editing and REST) & easier XMLText custom tags, Improved Media/Binary field types for cloud storage/CDN needs
Content (Search, ..), webshop, InfoCollector, RSS, Staging, tip a friend, Rating
For much more fine grained and additional technical info, see this community maintained Google spreadsheet.