See Mondo's Download page for details.
Mondo requires afio, bzip2, cdrtools/cdrecord, ncurses, newt, isolinux/syslinux, lzo (optional), lzop (optional), mkisofs, slang, and a few other packages.
Good Linux distributions provide all these packages. If yours does not then please go to the aforementioned Download page or surf the Net, preferably the website of the distribution you are using.
Mondo's expectations are not unreasonable, either of your Linux distribution or of your kernel. However, if your distribution fails to meet its expectations and you cannot find out how to resolve them, please feel free to e-mail the mailing list.