He did offer this work to the lucene project as a spatial contrib module.
The module was then extended with a GeoHash implementation.
3. What I tried to do in Lucene Spatial
My work on spatial lucene was some patches on projection to index space, grid matching cells ids calculation and some geo related calculation (bouding box and limit cases like prime meridian crossing or near pole bouding box calculations) in the Tile/Cartesian version only.
II- Current status of Spatial in Lucene
Today the spatial contrib in Lucene is marked as deprecated in 3.X of Lucene and shall be removed in 4.X
The spatial functionalities have been moved to Solr with a double NumericRange (latitude between (latmin, latmax) and longitude between (longmin, longmax)) type request and a GeoHash implementation.
No more Grid/Tile/Cartesian support and by moving spatial code to solr level this cut access to Hibernate Search users.
III- A new beginning
So I decided implement a Grid spatial search in Hibernate Search : Here was born hibernate-search-spatial.