it's this little shitty program called light map maker.
but it's quality is quite good for the first free program
i came upon search.

i was looking for gile(s) or something similar, apperantly
giles went free or open source or something way back but
i cannot find it anywhere.

edit. I think jcl should upgrade the lightmapper , if
I can get good looking radiosity like that in gs plus
be able to map a model I would definitely use it.