Build virtual machine images for vm-deployments; resize, un-partition, create from scratch or convert disk image files in a variety of formats; assemble and generate all associated files from templates and regular files. VM images can further be modifed through scripts, which are executed in LXC containers into which the vm-images as well as arbitrary directories from the host are mounted. All assembled files can also be accessed by vm build scripts through a special directory mounted in the build container, and/or can be written to directories, ISO- or VFAT-images. The ISO/VFAT images that B9 creates are compatible to 'cloud-init's NoCloud data source; B9 is also very well suited for compiling in a containerized environment. For these applications, the images can be marked as Transient to indicate no further interest in the VM-image itself, and B9 will discard them after the build. B9 will never over-write source files, not even large vm-image files - there is no intended way to modify a source vm-image file 'in-place'. B9 operates in random build directories, which are discarded when the build exists.