AisleRiot is a solitaire game that comes with Gnome. It's a lot like KPatience that comes with KDE. It provides a bunch of solitaire card games. However, the rules for Spider in AisleRiot are slightly different than the rules in Spider in KPatience. In KPatience, it is allowed to have an empty slot when laying out the next series of cards. In AisleRiot, this is not allowed. There are tactical advantages to allowing an empty slot, and the way I learned to play, it was allowed to leave one or more slots empty when turning up a new pile.