John Carmack (@ID_AA_Carmack) is a legend. He has been a legend (in our opinion) since Commander Keen was released in 1990 for Id Software. In the world of 3d gaming John and his team has had many breakthrough hits with Wolfenstein 3D, Doom and Quake series. When it comes to achievements Carmack has runs on the board.
Which is why many ears were pricked by his keynote at Quakecon 2013 when he shared his thoughts on functional programming and especially Haskell. He speaks very enthusiastically on the benefits of immutability and how software becomes more compositional, easier to reason about and less likely to break when embracing a “brutally pure” language such as Haskell.
If you needed examples of Haskell in “the real world”, this talk will be one for your armoury.
You can find the talk here on YouTube.