This one is called Sockso....personal music server.
http://sockso.pu-gh.com/Sockso is a free, open-source, personal music server for everyone! It's designed to be as simple as possible so that anyone with a mouse and some mp3's can get their friends listening to their music across the internet in seconds!
Features
•Simple setup (no install! just double click and go!)
•Supports MP3, OGG Vorbis, Flac, and WMA
•Easy web-interface for your friends, and a GUI for you!
•Online flash music players, playlists, search, etc...
•Download single tracks, or entire albums/artists or playlists
•Statistics like most played, recently popular, etc...
•Completely customizable/skinnable web interface
•User and site playlists
•Gui-less console mode for running on servers
•User account control, with playlists
•Uploads from users
•Album art for artists and albums
•Re-encoding of output streams to save bandwidth if needed
•Cover Flow style artwork view
•Last.fm related artist and scrobble log integration
•Multi-format access logs
•SSL support
•Translations: Dutch, Norwegian, Spanish, French, Italian and German
This one has been working awesome!
it does support files other than mp3 as long as you install the encoders, it did seem a bit finicky on flac and mp4 but mp3 flows awesome.
you can allow uploading if you wish, you can even create login names/passwords so only people with that info can login.
it uses a pop up flash player on the users end, so you need to have that installed for it to work.'
feel free to check out mine, I have not created a user/pass yet, so it is open. Beware, my music taste is somewhat eclectic, so I have a lot of different things on there

and I do not have uploading allowed. Hover your mouse over the buttons to see which does what, some will play / download / add to a playlist. also browse by letter, latest added, most played, etc.... play the whole album, whole artist, or certain song depending on which "play" button you hit, songs playing will list in the pop up player.
Some of my music was recorded from internet radio streams, so some songs have clipping, or maybe the end of one song before playing the desired song. that is the way the track was recorded, not a glitch in this program.....I am in the process of deleting those songs as I here them.
Check it out here:
http://baxtr.homeip.net:5050
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