This year, Blizzard Entertainment - the developers behind series like Warcraft, StarCraft and Diablo - turns 20. To celebrate, they've released this fascinating video retrospective.

It tells a story most of you have probably never heard, at least not to this level of detail: of nerds collecting money to start a development studio, of making Super Famicom games using Japanese-language documents, of Vikings who don't know where they are and some little games called Warcraft and StarCraft.

It's a long movie, so don't just click expecting a 90-second hit of history. Get a cup of tea, close the door and settle in. And know they don't skimp on talk of coding.

You can watch all 48 minutes of it at the link below.