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
Michaelangelo's hammer A young man named Michelangelo stands in front of a huge granite monolith. He stands there at a time in history before the technologies that brought us the hammer and chisel have occurred. He gazes at the rock. He dreams his dream and the best that he is able to say is, What a wonderful stone you are. … Michaelangelo now stands in front of the same rock. Thrust into his hands are a hammer in one and a chisel in the other. He looks at his hands, at the technological tools that they hold, and gazing at the same stone, with epiphanic zeal, says I must let Moses out. Richard Saul Wurman, Understanding Understanding Constrained by the medium tools