this is nawcom's MOD CD, to be written to a disc
the MOD CD disc is then booted, then the official snow leopard installation disc is booted from that
this MOD CD is both a 10.6.x kernel and bootloader combined.
this MOD CD kernel will not work with 10.6.8 and you need nawcom's 10.6.8v2 kernel for that, available here: http://www.insanelymac.com/forum/files/file/182-amd-1068v2/
i wrote a full guide here for a 10.6.8 install here: http://www.insanelymac.com/forum/topic/288474-simple-steps-to-amd-hackintosh-stable-everything-working/
i originally found this file here: http://nawcom.com/osx86/ModCD/OSX86_ModCD-091512-143758.iso.zip