Lean & Mean Software
I like this. Someone took the very first IBM PC ever made and managed to display full 30 frames-per-second video with audio on it. The machine is something like 4.7MHz! The video shows a demonstration.
If only all software were this performance-conscious. It’s amazing to see what people can get away with when they’re focused not on building new features but on tightening, tightening, tightening down existing features and making them perform as well as possible. This example showcases such extreme optimization. Very impressive.