I found a patent with active status apparently claimed the linked-list data structure.
A computerized list that may be traversed in at least two sequences comprising: a first sequence of items that comprise said list; and a primary pointer and an auxiliary pointer for each of said items of said list, said primary pointer being adapted to direct a computer program to a first following item and defining a first sequence to traverse said list, said auxiliary pointer being adapted to direct said computer program to a second following item and defining a second sequence to traverse said list.
I wonder even though the data structure is patented, how on earth almost every system is using this data structure without being sued by the assignee? If the assignee wants can he/she sue for using the claimed data structure?
What am I missing?
Note: Post corrected as pointed out by Eric S