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
Prometheus A Poem by Lord Byron www.poetryfoundation.org The lightnings trembledThe sum of human wretchednessMaking Death a Victory Subjected to some great trialA hierarchical system of senseYou find reasons to keep living deathsufferingpain
The lightnings trembled And in thy Silence was his Sentence, And in his Soul a vain repentance, And evil dread so ill dissembled, That in his hand the lightnings trembled. idefiancesilence
The sum of human wretchedness Thy Godlike crime was to be kind, To render with thy precepts less The sum of human wretchedness, And strengthen Man with his own mind; But baffled as thou wert from high, Still in thy patient energy, In the endurance, and repulse Of thine impenetrable Spirit, Which Earth and Heaven could not convulse, A mighty lesson we inherit.
Making Death a Victory Like thee, Man is in part divine, A troubled stream from a pure source; And Man in portions can foresee His own funereal destiny; His wretchedness, and his resistance, And his sad unallied existence: To which his Spirit may oppose Itself—and equal to all woes, And a firm will, and a deep sense, Which even in torture can descry Its own concenter'd recompense, Triumphant where it dares defy, And making Death a Victory. deathdestinyhumanity