For this one, a RGB LED bar is controlled wirelessly, with an Arduino. The Arduino does not have to be connected to a host PC since it has a wifi module attached. The module provides a tcp server feature that I use to make a basic http server. I just have to power the arduino and that is it!
The main advantages of this implementation are:
1. no need for a PC to work - just a wireless network
2. browser interface - no need for extra software and accessible from multiple devices