I currently have a headless home server set up (running Ubuntu 12.04 server edition) running a simple Apache HTTP server. The server is near an audio receiver, which controls a set of indoor and outdoor speakers in my home.
Recently, my father purchased a Bluetooth adapter, which our various laptops and cellphones can connect to, outputting the music to the speakers. I was hoping to find a solution that worked over my home network (Wi-Fi or ethernet), namely because it won't cost anything (I already have a server with an audio card), and it doesn't depend on Bluetooth.
Is there any cross-platform (preferably free and open-source) solution that I can use which will allow me to stream audio to my home server, over my home network? If possible, I'd like to stream from a wide variety of devices (laptops running Windows/Linux or cellphones running Android/BB/iOS) - but at minimum, I need something that works at least with Windows and Linux.
Also, just to clairfy, I want something that simply allows devices to connect to my server and output an audio signal without any action on the server end (since it's a server hidden away near my receiver). Any subsequent connection attempt should be dropped, so only one device can be in control of the stereo at once.
Example: Let's say I have company over at my home, and they all have smartphones. One person can connect to my server and begin playing audio. If someone else wants to play some of their music, the first person disconnects, and someone else can then stream their music to my server (which then plays on my speakers). I want to avoid storing the actual media on the server (aside from caching purposes).