It's easy to take the modern user interface for granted, in particular the mouse cursor. Point. Click. Repeat. Sure beats the heck out of using a keyboard all the time. Who do have to thank for this electronic and software marvel? Video time!
Over on the YouTube channel Posy, you'll find a great 15-minute clip covering the history of the humble mouse cursor, going as far back as Douglas Engelbart's "The Mother of All Demos" in 1968, the precursor to the graphical user interfaces we use today.
Xerox PARC adopted Engelbart's ideas, culminating in the Alto computer system, which was ground-breaking for its time.
What's interesting is the evolution of the cursor itself. For instance, Engelbart's was a short, vertical line with a small arrow top. This was iterated on, with some designs more successful than others, until the left-angled pointer became commonplace.
The video's creator finishes by making his own cursor, which is worth watching if you have an interesting in UIs or design.