SATIE for Spatial Audio Toolkit for Immersive Environment is a 3D audio scene renderer based on SuperCollider. It can render hundreds of live audio sources for large loudspeaker configurations.
Source code available here.
switcher is a multichannel streaming engine handling audio, video and data.
Source code and up to date information can be found here.
shmdata is a library enabling the sharing of live data streams between applications. It can be compared to the jack audio connection kit or syphon. While it supports any king of data streams, like audio, video, or what you want, it is using system shared memory.