In the continuing development of his online PHP-based game, Pádraic Brady has created a simple class to help with mapping out the objects/structures in the game. He shares the code for this in his latest blog post.
The code sets the stage for the Redux mapping system. Basically, we're aiming at a grid-based map with each grid coordinate representing a Sector.
Right now, it's just a skeleton structure, but it already has some of the key bits of functionality in place. The Redux_Map class manages the requests coming back and forth between the client and server, and the Redux_Map_Grid class helps to generate a grid structure of the objects found in that sector.
He even includes the unit tests for testing the Redux_Map_Grid class to ensure everything's in tip top shape. Next on his list is adding actual entities to the game - planets, facilities, etc.