Snow Leopard could boot in 32-bit, 64-bit, or legacy (32/64) kernel modes. MultiBeast 3.10.1 allowed you to choose kexts based on your kernel architecture – a feature lost in later OS versions.
MultiBeast 3.10.1 was part of the movement toward It aimed to remove the requirement for a patched DSDT for many common hardware configurations, instead relying on "kexts" (kernel extensions) to inject necessary hardware information at boot. Multibeast 3.10.1 - Snow Leopard