The problem with trees Many systems are organized hierarchically. The CERNDOC documentation system is an example, as is the Unix file system, and the VMS/HELP system. A tree has the practical advantage of giving every node a unique name. However, it does not allow the system to model the real world. For example, in a hierarchical HELP system such as VMS/HELP, one often gets to a lead on a tree such as: HELP COMPILER SOURCE_FORMAT PRAGMAS DEFAULTS only to find a reference to another leaf: Please see HELP COMPILER COMMAND OPTIONS DEFAULTS PRAGMAS and it is necessary to leave the system and re-enter it. What was needed was a link from one node to another, because in this case the information was not naturally organized into a tree. Tim Berners-Lee, Seeing With Fresh Eyes A City Is Not a Tree hierarchywww
Cool URIs don't change An Essay by Tim Berners-Lee www.w3.org What makes a cool URI? A cool URI is one which does not change. What sorts of URI change? URIs don't change: people change them. The User Interface of URLs www
The Love Song of J. Alfred Prufrock A Poem by T.S. Eliot www.poetryfoundation.org A pair of ragged clawsDo I dare disturb the universe?That is not it at allI have heard the mermaids singing lonelinessmelancholy
A pair of ragged claws I should have been a pair of ragged claws Scuttling across the floors of silent seas. i
Do I dare disturb the universe? Do I dare Disturb the universe? In a minute there is time For decisions and revisions which a minute will reverse. time
That is not it at all It is impossible to say just what I mean! But as if a magic lantern threw the nerves in patterns on a screen: Would it have been worth while If one, settling a pillow or throwing off a shawl, And turning toward the window, should say: That is not it at all, That is not what I meant, at all. meaning
I have heard the mermaids singing Shall I part my hair behind? Do I dare to eat a peach? I shall wear white flannel trousers, and walk upon the beach. I have heard the mermaids singing, each to each. I do not think that they will sing to me. melancholy