We have been using gnump3d as the music server for some 3 years in our college. But as of now the development of it has stopped and it is not that much reliable anymore, as it crashes whenever the server is restarted. Is there any other open source Music servers that can be used?
Yes, Plex Media Server can be used to stream media. Windows OSX and Linux solutions are available.
There is a list of some on Wikipedia. However, picking one depends on what kind of set-up you have, and of course there are more out there then those on the list!
For example, if you have Sonos system(s) set-up where you are streaming then perhaps you might want to use their own system. On the other hand, if you just want to have literally a server which contains all your music that can be accessed from PCs connected to the same network then you might want to use some Windows Media Player powered solution.