Graphical User Interface. A means of controlling or operating a system through the use of interactive graphics displayed on a screen. Examples in the computer world are the Apple Macintosh and Microsoft Windows, both designed for general-purpose use and usually operated with a mouse as the pointing device.

In 1981 Quantel introduced Paintbox with its on-screen menu system operated from a pressure sensitive pen and touch tablet. This purpose-built control has been further developed to cover a wide range of operations including DVEs, editing, VTR control, color grading and audio, and today is applied to the whole range of Quantel products. Besides its success in offering fast and effective control, the GUI also enables easy updates to accommodate new facilities.