Logitech Media Server!

Ampache is a web based audio streaming application and file manager allowing you to access your music from anywhere, using almost any internet enabled device.

Madsonic is a web-based media streamer and jukebox fork of Subsonic Based on Java technology, Madsonic runs on most platforms, including Windows, Mac, Linux, OSX, and Unix variants.

AudioStreamer is a free web-based audio streamer which gives you easy access to your music. It turns your PC in a streaming webserver. So you can listen to your music from everywhere and on any device(tablet, desktop, smartphone, ...) with a webbrowser..

Sockso is a free, open-source, personal music server for everyone! Its designed to be as simple as possible so that anyone with a mouse and some mp3s can get their friends listening to their music across the internet in seconds!

VortexBox is a free, open source (GPL v3), quick-install ISO that turns your unused computer into an easy-to-use music server/jukebox. Once VortexBox has been loaded on an unused PC, it will automatically rip CDs to FLAC and MP3 files, ID3 tag the files , and download the cover art. Vortexbox will then serve the files to network media players such as Logitech Squeezebox, Sonos, or Linn. The music files can also be streamed to a Windows or Mac OSX system.

A music streaming server written in python,

The Daphile is the heart of a digital music system. Its primary focus is in storage and playback of your digital music library. It enables the best possible audio quality and future-proof flexibility by providing plug&play support for USB connected digital-to-analog converters (DAC). You can easily setup a multi-zone system just by connecting another USB DAC for each zone.

Jinzora Media Server is a web based media streaming and management system, allowing you to stream your music and videos to any device with a web browser.

Listen to your music on multiple devices in sync share your music with friendsBuild a free multiroom audio systemConnect up to 16 devices simultaneouslyUse SoundSeeder with every existing Wi-Fi networkSupports Wi-Fi direct and Androids built-in portable HotspotFull-featured Music Player with Media Library and EqualizerDatabase with more than 4500 Online Radio StationsExperimental Google Music supportSoundSeeder is supported by Android 4.1+Speaker App available for Android 2.2+Windows and Linux Speaker Application (Raspberry Pi support) »

libresonic - Media streaming software

AirPhones is an app that sends perfectly synced audio from your computer to your iPhone or iPad with no latency. It's a next-generation, solution to wireless headphones.

MinimServer is a new UPnP AV music server with a number of innovative features that make it easier to organize and explore your music collection. If you have a network music player that supports the UPnP AV standards, you'll get much more from your music collection if you're using MinimServer as your music server software.