We believe that isakmpd currently addresses all mandatory features in the RFCs. We also implement most optional features. isakmpd currently runs on OpenBSD's old IPsec stack with PF_ENCAP, OpenBSD's current stack with PF_KEY, FreeS/WAN with Linux NetLink API and FreeBSD/NetBSD with KAME's IPsec stack via PF_KEY. We have also made it possible to shave off much of the extras at compile time, thus making isakmpd a candidate for being used in small embedded systems. isakmpd is in production used in numerous sites.