DemoBlaster is a hardware project capable of showing graphics on a 32x16 true color LEDs and playing audio. Based on a Raspberry Pi and using the fadecandy hardware, this is a nice piece of hardware to code demos for.
Slides for a lightning talk: DemoBlaster.pdf (Size: 1875520; Date: 2015-12-27, 20:17 CET)
The talk can be seen at media.ccc.de.
A small library has been created that contains some (more or less) useful stuff for coding demos, like playing audio (using OggVorbis), extended libgd functions, color management and sending data using OPC. Especially with the demoblaster in mind, it might prove still useful for other things.
This library is available as source code and precompiled for Raspbian Stretch at my private repository.