This is a simplified version of the original UNIX timeline (new window). I oversimplified many connections and left out all versions that have either died out or never got themselves started or were running parrallel to an existing newer or older version (this includes 2.xBSD when 4BSD was already out and the odd Linux kernels like 2.1 and 2.3). I also sometimes moved the release date one year to make the release fit better in the tree. The original UNIX release are all there, even though they lead practically nowhere.

On a last note I thought I should mention that the color codes I used are rather arbitrary but make some sense. I also tried to let trademark UNIX systems appear on the left side of the middle while non-trademark UNIX systems (or clones) appear on the right side.