The project uses Ethernet to control the LED matrix.
The authors used Arduino UNO and W5100 Ethernet Shield, and controlled the LED matrix using a protocol called Art-Net.
Art-Net is actually a protocol for DMX over ethernet.
The author uses a program called Jinx, which can send various LED matrix effects via Ethernet.
Arduino displays various effects on the LED matrix.
I think this project will help if you want to implement an LED matrix using Ethernet.