A list of the unallocated parts of a sharable resource. Some resources, such as processors, are shared by being allocated in their entirety to a process for a period of time. Other resources consist of a number of functionally similar units, e.g. pages within memory, and the resource is shared by units of the total resource being allocated to a process. This allocated share remains with the process until the process releases it. The available list provides the resource controller with a convenient record of which parts of the resource are not allocated to a process. See also free-space list.