I always thought it had the same meaning as in poker, i.e. the best possible low hand in a high / low game[1] and came about because the root user has id zero.

I always thought it had the same meaning as in poker, i.e. the best possible low hand in a high / low game[1] and came about because the root user has id zero. [1]: http://www.poker-vibe.com/poker/terms/wheel/ http://www.poker-vibe.com/poker/terms/wheel/