They are all patented, you just have not seen the relevant patents (or if you had seen them you would not be able to understand them). There was a story not lo

They are all patented, you just have not seen the relevant patents (or if you had seen them you would not be able to understand them). There was a story not long ago about how somebody had patented doubly linked lists (or maybe how to traverse a double linked list, I can't remember the details, but it was just as obvious).