A strange little side quest
The mechanics around Single Line have roots that stretch far beyond modern browsers. The first crossword puzzle book appeared in 1924 in a cautious initial printing of 3,600 copies, complete with a free pencil. The surprising part is how quickly the next milestone followed. Pong was field-tested in California bars in 1972 and helped launch the modern arcade-game era. That gives Single Line a little more company than it first appears to have.