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
Interoperable Personal Libraries and Ad Hoc Reading Groups An Article by Maggie Appleton maggieappleton.com We would need a system that enables people to: Publish a list of books they would be willing to discuss with other people to the open web. Antilibraries – collections of books you haven't read yet but would like to read – are particularly well suited to this proposition. See which books people in their social network want to discuss, and/or subscribe to other people's lists Be notified when 4+ people in their network have the same book on their discussion list – possibly via an email thread? Coordinate and schedule a time to read and discuss the book with that group. readingbooksnetworks