In early stage of development - updates soon!
Boxmaker runs well on OpenSUSE Tumbleweed and it's the recommended host OS.
It's also able to recompile itself (BoxLinux as host OS).
ISO image for VBox and Hyper-V.
The documentation is in html format, BOXLINUX_HOWTO.html but is still work in progress.
eMail me at george.naumov@outlook.com