How to open a node edit form in an overlay (modal window) in Drupal 8 I have a view with nodes of type 'tasks'.
I want to easily view and edit these tasks by using a minimized overlay. When I click on a task title in the view, it needs to open in an overlay.

In D7 this was possible with the core overlay module, in combination with 'Overlay Paths" module. 
The core overlay has been discontinued in D8, in favor of a 'back to site' link, which does not serve my purpose to show a minimized popup block. It also needs to be used by authenticated users, not only administrators.

How can this be done in D8?
You can do that by constructing special links with the help of Colorbox and Colorbox Inline. You'll probably have to create your own style for the "minimized" overlay. 

There are other libraries that do the same or similar thing as Colorbox, also integrated into Drupal through a module, so you might want to search and investigate others too (Shadowbox, for example). 

These modules are also worth checking out: Modal Configuration, Simple Modal Entity Form, Entity Overlay.