AF_UNIX on linux supports SOCK_DGRAM and SOCK_SEQPACKET in addition to SOCK_STREAM, so having message based interfaces won't be much of a change for some users.

AF_UNIX on linux supports SOCK_DGRAM and SOCK_SEQPACKET in addition to SOCK_STREAM, so having message based interfaces won't be much of a change for some users. SOCK_DGRAM at least appears to be widely supported (FreeBSD & Illumos & OpenBSD). SOCK_SEQPACKET is at least supported by OpenBSD (I'm going by what's in various docs/man pages).