The GPU Progressive Lightmapper is a GPU-accelerated version of the Progressive Lightmapper. The only user-facing difference is (ideally) a drastic performance boost (~10x), while maintaining feature parity. The CPU version of the Progressive Lightmapper will be maintained for developers without powerful GPUs. Also, the installed main memory in PCs usually exceeds the installed video memory so for some very large worlds, the CPU Progressive Lightmapper is the only viable option.