I've made an open-source library for fast spatial search in Rust.
It's called Spart, and it currently provides the following features:
- Five tree implementations: Quadtree, Octree, Kd-tree, R-tree, and R*-tree
- Python bindings (`pyspart` on PyPI)
- Fast k-nearest neighbor (kNN) and radius search
- Bulk data loading for efficient tree construction
Project's GitHub repo: https://github.com/habedi/spart