It works with a number of file formats (http://www.frecle.net/giles/fileformats.htm).
You can download a free trial version of gile[s] here (http://www.frecle.net/giles/download.htm).
Here's a quote from their website with a description of their product:
gile[s] is a global illumination / radiosity lightmapper, capable of rendering high resolution lightmaps fast and efficiently. gile[s] features an easy to use editor, that allows you to place models and lights without fuzz. Unlike most lightmappers gile[s] handles models of arbitrary complexity keeping smoothing groups intact. With gile[s] you can even paint directly to the lightmap, and mix and match vertex lighting and lightmaps as you please. gile[s] lights up your worlds.