OPNsense yog qhov chaw qhib, FreeBSD-raws li firewall thiab routing software tsim los ntawm Deciso, ib lub tuam txhab nyob rau hauv Netherlands uas tsim kho vajtse thiab muag cov pob khoom txhawb nqa rau OPNsense. Nws yog rab rawg ntawm pfSense, uas nyob rau hauv lem twb forked los ntawm m0n0wall ua rau FreeBSD. Nws tau pib thaum Lub Ib Hlis 2015.