The author has been working on adding support for MongoDB 2.4's geospatial query operators to Doctrine MongoDB, an abstraction for the PHP driver that provides a fluent query builder API. The introduction of read preferences last year posed a challenge in developing the library, which now invokes setReadPreference() if it exists in the driver and falls back to the deprecated setSlaveOkay() method otherwise. The author has also been working on adding support for MongoDB's new 2dsphere index type, which accepts GeoJSON geometry objects, and has implemented a GeoJSON library for PHP that can be used with Doctrine MongoDB. The library performs its own validation, catching errors such as open LineStrings in Polygons.