Definitely enough to make you trip
A GIS interface for CTR (aka Trippy)
Compact representation of Multidimensional data on Hierarchical Domains
The kn-treap is a straightforward extension of the k2-treap to manage multiple dimensions.
RePair implemented by Gonzalo Navarro adapted to C++.
CBM - Compact representation of Brownian Motion
Versión en C do k3-tree (lidar)