A decade ago I first presented a lightning talk entitled Cool Code. This short talk evolved into a full talk whose iterations I presented over the next half decade. The focus? Code that, for some reason or other, can be considered cool. For example, code that has played a significant role in historical events, such as the source for the Apollo Guidance Computer. Or code that is audacious — if not seemingly impossible — given its constraints, such as David Horne’s 1K chess. There is code that is both simple and profound, such as Peter Norvig’s fits-on-a-slide spelling corrector. And code that demonstrates ingenuity and humour, such as Yusuke Endoh’s Qlobe.