The library of babel started as a thought experiment but this person built it digitally. It is an algorithm that produces books of a fixed length and all of the books together contain every possible combination of letters and spaces (up to the fixed length). This means you can search for any string and find it's pre-existing coordinate in the library. But browsing the library manually you could spend your whole life and never find anything meaningful. It's partially a proof of the scarcity of functionally specified information in an even distribution of chaos.