If you’ve ever run into a dreaded configure problem such as C compiler cannot create executables, and gotten lost in a tangle of glibc/cc/g++ packages, you might find that building source rpms using Mock turns a multi-step process into a breezy single step. Build source rpms using mock which builds inside a chroot. This lets you compile 32-bit on 64-bit without a problem. Check out mock configurations in etc. You may have preconfigured configurations for your Linux distribution.

QEMU is a generic and open source machine emulator and virtualizer. When used as a machine emulator, QEMU can run OSes and programs made for one machine architecture on a different machine architecture. This is different than VMware, VirtualBox, or Hyper-V where you’re running different operating systems on the same architecture.