The space of all integers. See IntegerRegion, XuInteger, and IntegerDsp for interesting properties of this space. Especially IntegerRegion. IntegerSpaces? are the most frequently used of the coordinate spaces. XuArrays? are an efficient data structure which we provide as a table whose domain space is an integer space. In so doing, the notion of an array is made to be simply a particular case of a table indexed by the positions of a coordinate space. However, IntegerSpaces? and XuArrays? are both expected to be more efficient than other spaces and tables built on other spaces.