Sones-bstindex-tutorial is a project mainly written in ..., based on the AGPL-3.0 license.
a BinaryTree Index Tutorial
binary search tree index tutorial
This is the source corresponding to the custom index tutorial which can be found here:
http://developers.sones.de/wiki/doku.php?id=documentation:plugins:database:indices
It can be seen as some kind of template to implement own indices which can be integrated in the sones GraphDB.
Questions are alway welcome -> http://forum.sones.com