[iconfinder]

Can somebody provide some context for the video?

It's incredible to see how many of the concepts in this video is still present in a modern user interface.

[ozten]

The voice is Alan Kay who lead the invention of the modern day Desktop computer / GUI. The system is probably a prototype of the Dynabook, a laptop / tablet for children.

The code is Smalltalk which Alan and team created while inventing Object Oriented programming.

You can play with Squeak, which is the modern version of this system.