Fussy provide "embedded firmware" style upgrade mechanics (field upgrades) where a user uploads a (signed, possibly encrypted) package to your device and you want to verify, unpack and switch to running with that package. It provides a
back-off mechanic where a "failsafe" software bundle can be installed to which the system will back off in the event of a firmware upgrade failure.

Fussy is focussed on Linux machines, and should not be expected to work on any other platform. It expects to work on fairly "full" distributions, such as an Ubuntu Server LTS platform, but even a fairly minimal Debian distribution should work.