I believe that Max ships with Mental Ray licenses for 4 machines. Unlike the scanline renderer, all render nodes require that Mental Ray is licensed. Any more than 4 requires additional purchased licenses. The scanline renderer is unlimited. I've been using the scanline because I know it's fast. I haven't started to use Mental Ray yet. Is is easy to use? Is it as fast as the scanline renderer? I know that Max's scanline renderer is one of the fastest out there. Operaguy: That's funny. I've been refering to ours as "The Rack".