LightX is the module within my Project X engine that is responsible for generating, saving, and managing lightmaps. This tool generates lightmaps using a relatively simple lighting equation, packs them efficiently into a bitmap, saves the lightmap atlas to disk, and allows you to load a level and view the lightmaps in action.
LightX features the following (partial) list of features:
Simple linear math library
Perspective correct lightmapping
Bitmap file io
Simple resource management
Dynamic lightmap support
Project X map file support