http://nightlies.fireflymediaserver.org/ and I’d suggest grabbing 1586 as it’s good & stable & works well.
A couple of bug warnings: shorten the name firefly gives itself on first start-up – it bums out with super-long names. Also you may find that it hangs on the first scan – if it looks like that’s happening, let it run a few minutes then stop & restart the server and it should run fine. You should see Firefly running in Bonjour – to access the config file you may be asked for a u/name & p/w. Username leave blank, p/w should be mt-daapd or firefly. You can always access the config file at /yourusername/Library/Application Support/Firefly/firefly.conf
cheers, Andy