NDK is neuraldk's ongoing experimentation at creating a new, modern operating system. Currently in its infancy, it's of little use to anyone but the beginning operating systems developer.

Included in the download is a multi-boot compatible Kernel (which will require GRUB, or any other multi-boot compatible boot loader to run) and a floppy disk image suitable for VMWare, Bochs, or for dd'ing to an actually floppy (GRUB is included in the image).

From the GRUB menu, select the Current_Kernel option. MB_Kernel is not included in this download.
For some documentation on what's going on here, and the Multi-boot Standard, check out my tutorial on developing NDK thus-far: Creating A Multi-Boot Compatible Kernel

This site contains more information on ndk, and its progress.