Along with Borges and Cortázar, the Serbian writer Milorad Pavić was a great experimenter in non-linear narratives, creating dense labyrinths of prose, full of historical and mythical stories, parables and anecdotes and strange Balkan magic.
Most famously, his 'Dictionary of the Khazars' is composed of three different dictionaries - Christian, Islamic and Hebrew. Mixing historical fact with fiction, all three 'sources' are concerned with the Khazar people and the polemic surrounding their conversion from their own "to-us-unknown faith" into one of the three religions. Moreover, the book is available in two versions, a male and a female one, which differ in one crucial paragraph.
Pavić also experimented with digital hypertext - narratives that are non-linear as well as interactive. An interesting example is 'Damascene', subtitled 'A tale for computer and compasses'.
Another of his novels, 'Landscape Painted with Tea', is also a crossword puzzle, complete with a solution printed upside-down at the end of the book. Here's a short vignette from it, titled 'The Man Who Invented the Zero'.
The man who invented the zero came back after many years to the marketplace where, before he invented the zero, he had liked to sit and think. He used to sit here and think about how the unriddling of unknown laws and their implementation was our life. He used to think about this sitting on a rock amid the trash cans in the marketplace, because all the other, nicer spots in the square were always taken whenever he came by. There was a stone bench with a superb view that especially caught his eye, but that spot in particular was out of the question, because it was always claimed by somebody else. There was always somebody already sitting there. And so he invented the zero sitting on his rock amid the trash cans.
Now, when he returned so many years later to this place where he had invented the zero, it was winter, and all the seats in the square were empty. He could have his choice. However, he had come here not to invent the zero, because the zero he had already invented years before, but to sit once again in the spot where he had invented the zero and to remember how he had invented the zero. And so once again he headed straight for that rock by the trash cans. That spot was now his forever, and he could no longer choose.
And with a smile which was a bird forced to fly through water, he walked up to the rock by the trash cans, to his rock where he had invented the zero, but he did not stop. He walked on and finally installed himself on the beautiful stone bench with the superb view.
"I piss on the man who invented the zero," he said, sitting down.