This is a support library for Seeed Studio's Rainbowduino V3 LED driver board. This can be purchased as part of their Rainbow Cube Kit or on its own.
SeeedStudio maintains a wiki about these development boards at http://seeedstudio.com/wiki/Rainbow_Cube and http://seeedstudio.com/wiki/Rainbowduino_v3.0.
The version in this GitHub repo differs from the ZIP file in that it's been made compatible with the Arduino 1.0 environment. The use of WProgram.h was changed to be Arduino.h and the sketches were renamed to have the .ino extension.
Seeed released this code under the LGPL v.2.1 so you can use it with your own sketches as long as you provide a way for users to relink your sketch with an updated version of this library.