MediaLink and TwonkyMedia are the two uPnP servers I've found. Here's the pros/cons:
Twonky Pros:
One server that can stream to my Xbox 360, PS3, and Denon 3808
Handles all media formats (i.e. FLAC)
Twonky Cons:
Configuration is lame, can't handle multiple file formats well. Seems kinda glitchy.
MediaLink pros:
Well integrated with iLife
Clean config
Easy to use
MediaLink cons:
Doesn't seem to be ready to be a universal upnp server.
What I've tried to do is add my FLAC directory as a folder in MediaLink. I can browse to it but it is shown as empty. I assume because it won't send formats to the PS3 that it can't support. If it did this I would buy MediaLink in a heartbeat.
With Twonky it finds my FLACs just fine, and streams them just fine, but it mixes them in with anything else. So if you take the Album Crash by Dave Mathews Band it has every song in there twice - once as FLAC and once as MP3. I need both the MP3 and FLAC trees - not all my MP3s are available as flac. It'd be nice if I could browse through the actual file structure since the FLACs are all in their own directory.
Anyone have any other solutions (MAC ONLY) for this?