Simplifying a bit: It's a pedalboard with a Linux SBC inside where you can load LV2 plugins and chain and route them as you wish. It has a sleek web interface for management and some short of "pedal store". Like an advanced multieffects pedalboard. Originally the MOD devices where crowdfounded.
And Modep (as @tcrenshaw wrote in another comment) this is a MOD emulator for Raspberry pi, just in case you want to play with it: https://blokas.io/modep/