Abstract: Control and administration of the supply of memory managed in multiple heaps by a library heap management facility. Control data used by the heap management facility is located in user-supplied memory. Heaps are created dynamically through calls from the application to a runtime library. Allocation within a heap is performed through calls to the runtime library that canvass the available heap memory for each allocation request. If no suitable block of heap memory is located, additional user supplied memory is requested for the application through a callback function. A second callback function notifies the user when a supplied unit of memory is no longer required by the heap and may be disposed of. The callback functions are specified separately for each heap. The user may also set the default heap in the runtime library by allocation requests from a vendor library that do not specify a heap.