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
City messages So far the complete list of messages I've picked up from cities is: wealth, style, hipness, physical attractiveness, fame, political power, economic power, intelligence, social class, and quality of life. My immediate reaction to this list is that it makes me slightly queasy. I'd always considered ambition a good thing, but I realize now that was because I'd always implicitly understood it to mean ambition in the areas I cared about. When you list everything ambitious people are ambitious about, it's not so pretty. Paul Graham, Cities and Ambition Everybody worships