Music Servers-Why so few?

With the explosion of Dacs and discussions of computer audio one would think the server market would flourish as well. Where are all of the "big" names and their offerings? They can certainly produce Dacs. With the exception of Bryston, it seems the small companies are the only ones who offer something and then its a crapshoot as to who will be able to answer an email or have a decent website with useful information. Where are they?