TwentySevenTree

By Johan, this is a tree which can be used to construct a FileSystem or
graphical Z-order tree (Ultima 7 or 8 game.) You can read the [TwentySevenTreePythonCode]
for an example.

It was a part of my research at the university, I gave it to the hacker
community, you can use it for anything you want, nothing commercial unless you contact me
and do respect the licenses.

[TwentySevenTreeSchemeCode] is another implementation.