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
Turn them into cycles Permaculture systems seek to stop the flow of nutrient and energy off the site and instead turn them into cycles, so that, for instance, kitchen wastes are recycles to compost; animal manures are directed to biogas production or to the soil; household greywater flows to the garden; green manures are turned into the earth; leaves are raked up around trees as mulch. Bill Mollison, Introduction to Permaculture Two CyclesAn ecological cycle ecosystemsrecyclinggardens