From the specs:
Compatible cartridges
HP 63 and HP 63 XL (US)
HP 302 and HP 302 XL (Europe)
HP 803 and HP 803 XL (Asia)
So they just use HP inkjet technology. That makes it less open-source, but even "open source" parts are going to be under non-commercial license (CC BY-NC-SA) anyway.
> even "open source" parts are going to be under non-commercial license (CC BY-NC-SA) anyway
You're saying this as if it is a bad thing? I absolutely welcome this decision by the authors!