List columns now support using array names (eg: relation[attribute]) which acts as an alias for the valueFrom option with searchable and sortable disabled.

Form Tabs now support specifying a default tab using the defaultTab option (see Backend > Forms docs).

Improved the Theme management features: Edit properties, import, export, duplicate and delete.

Form fields can now use a simpler interface for using the Input preset converter (see Backend > Forms docs).

The event cms.page.init no longer passes the URL as the third parameter, $controller->getRouter()->getUrl() should be used instead.

Page::url() no longer takes a third argument for $absolute, generated URLs with this method are always absolute.

Improvements made to the user menu in the back-end: clicking your avatar will display a popover with settings links from the mysettings context.

Added new form field widget called repeater for repeatable fields (see Backend > Forms docs).

Made some UI improvements to the Rich Editor.

Form widget base class no longer takes a model as the 2nd argument, it should be passed as model in the configuration instead.

Introduce AjaxException that allows response contents to be sent to framework.js and still be treated as an error.

Report Widgets now support the use of AJAX event handlers.