Libguestfs is a C library that provides a way to access and modify virtual machine disk images. It uses qemu and the Linux kernel, so we can manipulate just about any disk image, filesystem, partitioning scheme, LVM, Windows disks, and more. Above this layer are many specialized "virt-*" tools for carrying out specific tasks. In this talk, Richard Jones will give a live demonstration of libguestfs and the virt tools, and talk about the new features available in libguestfs 1.20.