libguestfs vs OSFMount

libguestfs is a free library and toolset for working with virtual machine disk images. It can inspect and edit guest files, script changes, create or resize images, make backups, clone virtual machines and build them. The project says it can access almost any disk image, including those from VMware and Hyper-V, and images created by VMware, KVM, qemu, VirtualBox, Xen and other hypervisors; libvirt is not required. Its command-line tools include guestfish, a scriptable shell, and virt-rescue, an interactive rescue shell. The C library has bindings for many languages, with examples for C/C++, Erlang, Go, Java, Lua, OCaml, Perl, Python and Ruby. Guest filesystems are accessed through a Linux kernel in a qemu virtual machine, usually as a non-root user; sVirt with libvirt and SELinux can also be used. It runs on many Linux distributions and Mac OS X, while some virt tools have been ported to Windows. Non-Linux systems may require compiling from source and porting.

OSFMount has no write-up on Specifiction yet; its figures are above.