UNIX Family 'Tree'

digraph unix { fontname="Helvetica,Arial,sans-serif" node [fontname="Helvetica,Arial,sans-serif"] edge [fontname="Helvetica,Arial,sans-serif"] node [color=lightblue2, style=filled]; "5th Edition" -> "6th Edition"; "5th Edition" -> "PWB 1.0"; "6th Edition" -> "LSX"; "6th Edition" -> "1 BSD"; "6th Edition" -> "Mini Unix"; "6th Edition" -> "Wollongong"; "6th Edition" -> "Interdata"; "Interdata" -> "Unix/TS 3.0"; "Interdata" -> "PWB 2.0"; "Interdata" -> "7th Edition"; "7th Edition" -> "8th Edition"; "7th Edition" -> "32V"; "7th Edition" -> "V7M"; "7th Edition" -> "Ultrix-11"; "7th Edition" -> "Xenix"; "7th Edition" -> "UniPlus+"; "V7M" -> "Ultrix-11"; "8th Edition" -> "9th Edition"; "1 BSD" -> "2 BSD"; "2 BSD" -> "2.8 BSD"; "2.8 BSD" -> "Ultrix-11"; "2.8 BSD" -> "2.9 BSD"; "32V" -> "3 BSD"; "3 BSD" -> "4 BSD"; "4 BSD" -> "4.1 BSD"; "4.1 BSD" -> "4.2 BSD"; "4.1 BSD" -> "2.8 BSD"; "4.1 BSD" -> "8th Edition"; "4.2 BSD" -> "4.3 BSD"; "4.2 BSD" -> "Ultrix-32"; "PWB 1.0" -> "PWB 1.2"; "PWB 1.0" -> "USG 1.0"; "PWB 1.2" -> "PWB 2.0"; "USG 1.0" -> "CB Unix 1"; "USG 1.0" -> "USG 2.0"; "CB Unix 1" -> "CB Unix 2"; "CB Unix 2" -> "CB Unix 3"; "CB Unix 3" -> "Unix/TS++"; "CB Unix 3" -> "PDP-11 Sys V"; "USG 2.0" -> "USG 3.0"; "USG 3.0" -> "Unix/TS 3.0"; "PWB 2.0" -> "Unix/TS 3.0"; "Unix/TS 1.0" -> "Unix/TS 3.0"; "Unix/TS 3.0" -> "TS 4.0"; "Unix/TS++" -> "TS 4.0"; "CB Unix 3" -> "TS 4.0"; "TS 4.0" -> "System V.0"; "System V.0" -> "System V.2"; "System V.2" -> "System V.3"; }