graph: {title: "unix evolution"
        layoutalgorithm: tree   // Yes, this is actually not a tree.
        scaling        : 2.0
        colorentry 42  : 152 222 255
        node.shape     : ellipse   //=================================
        node.color     : 42        //   aiSee -- Graph Visualization  
        node.height    : 32        //       http://www.aisee.com      
        node.fontname  : "helvB08" //     © Copyright 2000 - 2002     
        edge.color     : darkred   //AbsInt Angewandte Informatik GmbH
        edge.arrowsize :  6        //         aisee@absint.com        
        node.textcolor : darkblue  // Courtesy I. Darwin & G. Collyer 
        splines        : yes       //=================================
node: {title: "5th Edition"}  node: { title: "6th Edition" }
node: {title: "PWB 1.0"    }  node: { title: "LSX"         }
node: {title: "1 BSD"      }  node: { title: "Interdata"   }
node: {title: "Mini Unix"  }  node: { title: "Wollongong"  }
node: {title: "7th Edition"}  node: { title: "Xenix"       }
node: {title: "32V"        }  node: { title: "UniPlus+"    }
node: {title: "V7M"        }  node: { title: "3 BSD"       }
node: {title: "4 BSD"      }  node: { title: "2 BSD"       }
node: {title: "4.1 BSD"    }  node: { title: "2.8 BSD"     }
node: {title: "4.2 BSD"    }  node: { title: "8th Edition" }
node: {title: "Ultrix-11"  }  node: { title: "2.9 BSD"     }
node: {title: "Ultrix-32"  }  node: { title: "4.3 BSD"     }
node: {title: "9th Edition"}

node: {title: "PWB 1.2"    }  node: { title: "USG 1.0"     }
node: {title: "PWB 2.0"    }  node: { title: "USG 2.0"     }
node: {title: "CB Unix 1"  }  node: { title: "Unix/TS 1.0" }
node: {title: "USG 3.0"    }  node: { title: "CB Unix 2"   }
node: {title: "Unix/TS 3.0"}  node: { title: "CB Unix 3"   }
node: {title: "Unix/TS++"  }  node: { title: "PDP-11 Sys V"}
node: {title: "TS 4.0"     }  node: { title: "System V.0"  }
node: {title: "System V.2" }  node: { title: "System V.3"  }

edge: {source: "5th Edition"  target: "6th Edition" }
edge: {source: "5th Edition"  target: "PWB 1.0"     }
edge: {source: "6th Edition"  target: "LSX"         }
edge: {source: "6th Edition"  target: "1 BSD"       }
edge: {source: "6th Edition"  target: "Mini Unix"   }
edge: {source: "6th Edition"  target: "Wollongong"  }
edge: {source: "6th Edition"  target: "Interdata"   }
edge: {source: "Interdata"    target: "Unix/TS 3.0" }
edge: {source: "Interdata"    target: "PWB 2.0"     }
edge: {source: "Interdata"    target: "7th Edition" }
edge: {source: "7th Edition"  target: "8th Edition" }
edge: {source: "7th Edition"  target: "32V"         }
edge: {source: "7th Edition"  target: "V7M"         }
edge: {source: "7th Edition"  target: "Ultrix-11"   }
edge: {source: "7th Edition"  target: "Xenix"       }
edge: {source: "7th Edition"  target: "UniPlus+"    }
edge: {source: "V7M"          target: "Ultrix-11"   }
edge: {source: "8th Edition"  target: "9th Edition" }
edge: {source: "1 BSD"        target: "2 BSD"       }
edge: {source: "2 BSD"        target: "2.8 BSD"     }
edge: {source: "2.8 BSD"      target: "Ultrix-11"   }
edge: {source: "2.8 BSD"      target: "2.9 BSD"     }
edge: {source: "32V"          target: "3 BSD"       }
edge: {source: "3 BSD"        target: "4 BSD"       }
edge: {source: "4 BSD"        target: "4.1 BSD"     }
edge: {source: "4.1 BSD"      target: "4.2 BSD"     }
edge: {source: "4.1 BSD"      target: "2.8 BSD"     }
edge: {source: "4.1 BSD"      target: "8th Edition" }
edge: {source: "4.2 BSD"      target: "Ultrix-32"   }
edge: {source: "4.2 BSD"      target: "4.3 BSD"     }
edge: {source: "PWB 1.0"      target: "PWB 1.2"     }
edge: {source: "PWB 1.0"      target: "USG 1.0"     }
edge: {source: "PWB 1.2"      target: "PWB 2.0"     }
edge: {source: "USG 1.0"      target: "CB Unix 1"   }
edge: {source: "USG 1.0"      target: "USG 2.0"     }
edge: {source: "CB Unix 1"    target: "CB Unix 2"   }
edge: {source: "CB Unix 2"    target: "CB Unix 3"   }
edge: {source: "CB Unix 3"    target: "Unix/TS++"   }
edge: {source: "CB Unix 3"    target: "PDP-11 Sys V"}
edge: {source: "USG 2.0"      target: "USG 3.0"     }
edge: {source: "USG 3.0"      target: "Unix/TS 3.0" }
edge: {source: "PWB 2.0"      target: "Unix/TS 3.0" }
edge: {source: "Unix/TS 1.0"  target: "Unix/TS 3.0" }
edge: {source: "Unix/TS 3.0"  target: "TS 4.0"      }
edge: {source: "Unix/TS++"    target: "TS 4.0"      }
edge: {source: "CB Unix 3"    target: "TS 4.0"      }
edge: {source: "TS 4.0"       target: "System V.0"  }
edge: {source: "System V.0"   target: "System V.2"  }
edge: {source: "System V.2"   target: "System V.3"  }
}