Lguest allows you to run multiple copies of the same 32-bit kernel: simply modprobe lg, then run Documentation/lguest/lguest to create a new guest.
I suggest you try this yourself - lguest is incredibly easy to get up and running. It's also quite useful: I can test-boot kernels with it in less than a second, or about 10x faster than basic qemu, and 100x faster than a real boot. And as it uses a pty as console, you can do things like pipe it through grep.
— Matt Mackall on linux-kernel
What's virtualization? How does lguest compare against XYZ? See our Frequently Asked Questions.
The lguest patch contains a Documentation/lguest/lguest.txt file, but you can also read it online.
The good news is: lguest is all one big kernel patch, including the launcher. It's in 2.6.23-git13 and above.. For usage, read Documentation/lguest/lguest.txt. For hacking, read drivers/lguest/README.
Those crazy guys at Red Hat have an experimental port of lguest to x86-64: you can grab their git tree.
Lguest has plenty! If you find one, please email me, and cc the virtualization list at linux-foundation.org.
We have a low-volume lguest mailing list for users and developers.
lguest, like all my Linux kernel work, is available under the under version 2 of the GNU General Public Licence (GPLv2) or (at your option) any later version.
Thanks to everyone working on other virtualization technologies. They are the reason I started lguest. Plus, the puppies! Puppies!