µGUI is a free and open source graphic library for embedded systems. It is platform-independent and can be easily ported to almost any microcontroller system. As long as the display is capable of showing graphics, µGUI is not restricted to a certain display technology. Therefore, display technologies such as LCD, TFT, E-Paper, LED or OLED are supported. The whole module consists of two files: ugui.c and ugui.h.