Shairport Sync emulates an AirPort Express for the purpose of streaming audio from iTunes, iPods, iPhones, iPads and AppleTVs. Audio played by a Shairport Sync-powered device stays synchronised with the source and hence with similar devices playing the same source. In this way, synchronised multi-room audio is possible without difficulty. (Hence the name Shairport Sync, BTW.)
Building this on OS X is not so straightforward, so I made the
homebrew formula for it.
Formula was accepted into homebrew repo, so now just run:
PS Building with libsoxr, libao and dns_sd