Persistent data structures are being imported from the FP world.
What makes persistent data structures particularly interesting is that they cannot be modified in the traditional sense. These structures can model a timeline of changes quite naturally since every "change" creates a new "copy".
"Functional Reactive Programming" is another old/new idea. FRP has a time centric viewpoint.
In this talk Danie will explain why persistent data structures are good and specifically why they are good for (the) UI.