Bret Victor – Inventing on Principle: This video is flat amazing. This guy has re-envisioned the entire concept and value of the IDE.
Watch the fist six minutes of it, and know that he’s just cracked the surface at that point and even better demos are coming up. At that point, I dare you to stop watching.
I have no idea if this IDE actually exists for real. I’m a little afraid to go look, frankly.