Ipkg was used in the Unslung operating system for the Linksys NSLU2 (Optware), in OpenWrt, Openmoko, webOS, Gumstix, the iPAQ, QNAP NAS appliances and elsewhere; as of early 2017 it can still be used for the Synology NAS appliances and in the LuneOS operating system (although opkg is an increasingly common replacement).
Head entity: opkg
Tail entity: ipkg
Relation (head \u2192 tail): followed by
Inverse relation (tail \u2192 head): follows